This surprisingly easy-to-make midwest pork tenderloin sandwich is succulent, tender and super crispy due to the buttermilk soak, breading and quick frying.
My partner AJ was born, raised and went to school in Indiana. And as such, he is QUITE particular about his fried pork tenderloin sandwiches. And though you can find the pork tenderloin sandwich in Iowa, southern Illinois and other parts of the Midwest, for me the sandwich is strictly an indigenous Hoosier dish. I’ve share various version of fried meat on this blog (my easy fried chicken, my Taiwanese popcorn chicken and my Japanese karaage) but I haven’t shared what my partner dubbed “the best pork tenderloin sandwich I’ve ever had.” High praise from AJ!
What is a Pork tenderloin sandwich?
Otherwise know by the old school set as a “pork fritter sandwich”, the breaded pork tenderloin sandwich is a piece of pork tenderloin that has been pounded flat until it is exceedingly long, then breaded, fried and placed on hamburger bun.
A proper pork tenderloin sandwich should overhang the bun enough that it’s noticeable! Ideally, the fried pork tenderloin should, at a minimum, be twice the length of the bun it is sitting on. According to my Hoosier partner, anything smaller than that, and you’re not eating a pork tenderloin sandwich, you’re eating a regular fried pork sandwich.
How do you make a pork tenderloin sandwich?
Making the pork tenderloin sandwich is surprisingly easy. First you cut up a pork tenderloin into 4 parts. Then you butterfly (cut partially) each piece and open it up like a book. Place a piece of plastic wrap on it and then pound away until you have a long, flat 8 to 10-inch wide piece of pork that is about 1/2-inch thick.
Soak the pork in a buttermilk (or a buttermilk substitute) and some spices before the frying process. The buttermilk is an acidic environment that helps tenderizes the pork further and the thick clinging liquid works well to help the subsequent breading adhere to the pork.
Once the pork has been sitting in the spiced buttermilk for a bit, take it out, dip it in flour, then beaten egg, and then bread crumbs. You can use store-bought bread crumbs but I like to use fresh breadcrumbs. I tend to cut up loaves of bread that I either baked or bought at a local bakery and any odd sized bits get tossed into a freezer bag, to be cut up for croutons or processed in a blender/food processor into crumbs.
Once all four pieces are breaded, you fry them in a large skillet in hot oil. Then place in between hamburger buns and garnish with the topping of your choice.
What do you put on the sandwich and what sort of bun should you use?
Like most sandwiches or burgers, the toppings are up to you. Standard toppings for a pork sandwich include:
- Lettuce, shredded or a nice big piece of leafy green
- Tomatoes, sliced big and thick
- Red onions, sliced thin
- Pickle slices
The bun is completely up to you! The classic white hamburger bun is traditional. But you can get fancy and serve it on a brioche bun or on a pretzel bun (which is what I serve it on). If you don’t have any of those, two slices of bread will totally work as well but that’s definitely not traditional (but then, neither is the pretzel bun!).
How do I substitute buttermilk?
If you don’t have buttermilk, you can still make a great pork tenderloin sandwich! Here are few options for substitutions:
- Acidified milk: Just add 1 tablespoon of lemon juice, apple cider vinegar or white vinegar to 1 cup of milk. Let sit for 10 minutes to thicken up, and then use that in place of the buttermilk. If don’t have vinegar or lemon juice, you can also mix in 1 3/4 teaspoon of cream of tartar into 1 cup of milk to acidified it.
- Plain yogurt with milk: mix together 3/4 cup of plain regular yogurt with 1/4 cup of milk.
- Greek-style yogurt with milk: Stir together 1/2 cup of Greek-style plain yogurt with 1/2 cup of milk
- Sour cream with milk: mix together 1/2 cup of sour cream with 1/2 cup of milk
- Sourdough starter discard: if you have a sourdough starter, you know sourdough discard multiplies! Use 1 cup of sourdough discard in place of the buttermilk in this recipe for excellent (some would say even better) results.
What can I use for the breading?
I like to use fresh breadcrumbs for the final coating of the crispy pork tenderloin. I place stale bread in a blender or food processor and pulse into crumbs form. But you can also use these various options instead. Just remember you need about 3 cups of whatever you are making.
- Crushed saltines: Press and crush saltines in a ziplock bag with the palm of your hand or a rolling pin. Or process it in a blender or food processor until crumbs form. Omit the salt in the bowl with the crumbs if your saltines are already salted.
- Crushed matzo: If you have leftover matzo from Passover or you normally stock matzo, crushed or processed matzo like the saltines work great. (Though obviously this would not be a kosher sandwich!)
- Storebought bread crumbs: Just measure out 3 cups
- Panko crumbs: These Japanese style bread crumbs are extra crispy. Just measure and use 3 cups.
How do you eat a pork tenderloin sandwich?
There are two competing schools of thought on the matter. One side believe you should eat the overhanging pork from the bun first, starting on one side and eating until you reach the perimeter of the bun and then flipping to eating the other side, until all the overhanging pork is finished. Then you proceed with eating the sandwich with the bun included.
The other school of thought is to fold or cut the tenderloin in half or in thirds, stack them inside the bun, and then eat as a double or triple decker pork sandwich.
There is no right or wrong way, though my informal survey on Instagram Stories found that about 70% of people fall in the eat the overhanging pork first school, with only 25% cutting or folding the pork.
(Oh, the remaining 5% said they immediately cut the pork in half and took half of it home to place on a different bun, thereby giving themselves two sandwiches for the price of one. But I’m discounting these outliers).
What are similar dishes to the Pork tenderloin sandwich?
A breaded or batter-coated and fried meat patty isn’t unique to just the United States midwest. There are similar dishes all over the world, though most feature the breaded meat patty by themselves or with various toppings. Few serve it in a sandwich form. Here’s a few similar dishes:
- Austrian Wiener Schnitzel: a veal cutlet that is breaded and deep fried (though pork is sometimes used instead of veal because it is cheaper). You’ll also find a popular chicken schnitzel version all over Australia, made with chicken cutlet instead of veal or pork.
- Japanese Pork Tonkatsu: a coated pork cutlet with panko crumbs and deep fried. It’s served with tonkatsu sauce, a sweet and tangy sauce
- Italian Cotoletta: a veal breaded cutlet, which there are various different types, some of which are served with a piece of prosciutto and parmesan on top, others are baked, grilled or made with bone-in pork.
- South American Milanesa: similar and inspired by the Italian Cotoletta. Different countries have different preparations with Argentina, Paraguay and Uraguay often topping it with an egg, while Mexico serving it in a torta as a sandwich.
- The United States has Chicken Fried Steak, Chicken Parmigiana and The Tennessee or Nashville Hot Chicken sandwich : the chicken fried steak is a similar cubed beef steak cutlet that is breaded and served with a cream gravy. Chicken parmigiana or Chicken Parm is an Italian-American dish that has a breaded and fried chicken cutlet covered with marinara sauce and parmesan cheese. And the Tennessee or Nashville Hot Chicken is a piece of spicy hot fried chicken served as a sandwich!
How to store leftovers
Though the pork tenderloin sandwich is best eaten fresh, you can refrigerate any leftovers for up to 3 days. Just warm up the pork tenderloin, by itself, in a preheated 350°F oven or toaster oven for about 10 to 15 minutes or until it is warm through. I don’t recommend the microwave to warm it up, as the crispy crust will get soggy.
Once warm, place the breaded tenderloin on the bun and add the garnishes and fixing and serve.
What to serve with the sandwich
As much as I love just eating a sandwich by itself, sometimes you need to add a side dish to make it feel complete. Here’s a few suggestions
- french fries
- tater tots
- potato chips, store bought or homemade if you’re feeling it
- onion rings (like my sourdough onions which can be made with buttermilk or a buttermilk substitute)
- Crispy oven fries
- esquisites, corn salad
- wedge salad
Pork Tenderloin Sandwich
- candy thermometer (recommended)
- Vegetable oil see headnote for recommendations
- Hamburger or bread buns
- Slice red onions
Cut the pork tenderloin lengthwise into 4 equal pieces.
Take one piece and partially cut it horizontally, leaving about 3/4-inch still attached. Open the piece so it lays flat, like a book.
Take a piece of plastic wrap, lay it over the pork and then pound the piece flat with a meat mallet or a heavy skillet, until it is about 1/2-inch thick and about 8 to 10 inches long. Repeat with the remaining 3 pieces of pork.
Combine the sourdough discard, salt, pepper, garlic, onion, paprika and cayenne into a glass measuring cup.
Place the pork in a 1-gallon resealable Ziploc bag, then pour the marinade into the bag. Seal it and then “massage” it until all four pieces of flatten pork are properly coated. Refrigerate for at least an hour (though 2 to 3 hours is optimum).
Once the pork is ready, place the flour in a large shallow dish (I like to use a pie pan or small casserole baking pan). Place the eggs in a second shallow dish. And place the bread crumbs in a third shallow dish or baking pan. Sprinkle 1 teaspoon of salt and pepper in the flour and in the bread crumbs. Sprinkle the remaining 1/2 teaspoon of salt and pepper in the eggs.
Remove one piece of pork from the plastic bag and place it in the flour, turning it to coat completely.
Beat the eggs until slightly frothy. Move the pork to the egg dish and turn it to coat.
Then place the pork in the bread crumbs, pressing firmly on the pork to adhere the bread crumbs to it, then flipping to make sure the other side is coated as well. Move the coated pork to a rimmed baking sheet and repeat with the remaining 3 pieces of pork.
When the pork is ready to be cooked, place a wire cooling rack on a rimmed baking sheet.
In a large saute pan (at least 10-inches wide) pour enough oil to come up 1/2-inch. Heat the oil until it is 350°F. If you don’t have candy/deep frying thermometer, place a 1-inch square bread cube in the oil. If it turns golden brown in 60 seconds, it is at the right temperature.
Pick up one piece of pork and place it in the oil. Put one side of the pork in the oil, then let go gently, allowing the pork to gently slide into the hot oil. Do not drop the pork from a distance because that will cause the oil to splash and potentially burn you. Just make sure part of the pork is in the oil and then let go.
Cook the pork about 2 minutes on each side, or until it is deep golden brown and the center of the pork reads 145°F. Move the pork to the wire rack and then repeat with the remaining pork.
Serve on a hamburger bun with the fixings of your choice (like lettuce, tomato, red onion and condiments)