This is a smash-style cheeseburger built around the same logic In-N-Out uses: fresh 80/20 beef, American cheese, crisp iceberg, ripe Roma tomato, and a tangy mayo-ketchup-relish spread. The honest reason to make it at home is that the technique is fast, the ingredient list is short, and the result is genuinely better than most burgers that take twice the effort.
The short version of why this works
Two things carry this burger. First, smashing the patty thin against a hot, dry cast-iron or stainless pan creates a proper Maillard crust — that browned, slightly crispy edge is where most of the beef flavor lives. Second, the spread goes on both buns, not just one. That even coating keeps every bite moist without making the bun soggy, and it ties the salt of the beef to the sweetness of the tomato in a way that a one-sided swipe just doesn’t.
Smart swaps
- Ground beef: 80/20 chuck is the target. Leaner blends cook drier and won’t give you the same crust. If your store only has 85/15, add a small pat of butter to the pan.
- American cheese: Stick with it. White cheddar melts unevenly on a thin patty and can turn greasy. American is the right call here — skip the egg in the mix, and skip the fancy cheese too; both work against the texture you’re after.
- Pickle relish in the spread: Sweet relish is standard. Dill relish makes the spread sharper and less sweet — fine if that’s your preference, but it reads differently.
- Bun: A soft white hamburger bun or a lightly toasted brioche both work. Avoid anything with a thick, chewy crust — it compresses the patty when you bite down and throws off the ratio.
- Onions: Yellow onions grilled low and slow go jammy and sweet. Raw white onion gives a sharper bite. Both are correct; it’s a matter of preference, not technique.
Troubleshooting
- Spread tastes flat: The vinegar is doing more work than it looks like. If the spread lacks brightness, add a few more drops — a quarter teaspoon at a time — and stir before tasting. Don’t reach for more ketchup first.
- Patty sticks to the pan: The pan wasn’t hot enough before the beef went in, or you tried to flip too early. A properly seared patty releases on its own. Give it another 20–30 seconds before forcing it.
- Cheese won’t melt fully: After laying the slice on the patty, add a splash of water to the far edge of the pan (not on the patty) and immediately cover with a lid or large bowl for 15–20 seconds. The steam finishes the melt without overcooking the beef.
- Bun goes soggy fast: Toast the cut sides in the same pan after the patty comes out — 30 to 45 seconds on medium heat is enough. Don’t skip this step if you’re building the burgers more than a minute before eating.
- Patty shrinks into a thick puck: The smash needs to happen within the first 10–15 seconds of the beef hitting the pan, before the proteins set. After that window, pressing down just squeezes out juice without flattening anything.
Make-ahead notes
The spread keeps well — mix it up to five days ahead and store it covered in the fridge. Formed but uncooked patties can be stacked with parchment between them and refrigerated for up to 24 hours, or frozen for up to two months; thaw overnight in the fridge before cooking. Cooked patties don’t reheat well in a microwave (they steam and toughen), but 2–3 minutes in a covered pan over low heat with a tablespoon of water keeps them reasonably juicy. Slice your tomato and prep your lettuce the morning of — both hold fine in the fridge, loosely covered, for several hours.
Classic In-N-Out Style Hamburger
Ingredients
For the Signature Spread:
- ½ cup mayonnaise preferably full-fat with clean flavor
- 2 tablespoons ketchup
- 1 tablespoon sweet pickle relish
- 1 teaspoon white vinegar
For the Burger Patties:
- 1.5 pounds ground beef 80% lean chuck, freshly ground for best flavor
- 1 teaspoon kosher salt
- ½ teaspoon freshly ground black pepper
For Assembly:
- 4 pieces hamburger buns soft brioche or classic white buns
- 4 slices American cheese or sharp cheddar for extra tang
- 1 cup iceberg lettuce shredded
- 2 medium roma tomatoes thinly sliced into rounds
- 1 medium yellow onion sliced thin, grilled or raw as preferred
- 2 tablespoons unsalted butter for toasting buns
Instructions
- Make the Spread: In a small bowl, mix the mayonnaise, ketchup, relish, and vinegar. Stir until smooth and creamy. Refrigerate while preparing the burgers to allow flavors to meld.
- Prepare the Patties: Divide the ground beef into 4 equal portions (around 6 oz each) and shape gently into thin, wide patties slightly larger than the bun. Season both sides with salt and pepper. Do not overwork the meat to keep it tender.
- Toast the Buns: Heat a skillet over medium heat and add butter. Once melted, place the cut side of buns down and toast until golden, about 1–2 minutes. Set aside.
- Cook the Patties: Heat a heavy skillet or grill pan over medium-high heat (about 375°F/190°C). Sear patties for 2–3 minutes until a crisp crust forms. Flip once, add cheese, and cook another 1–2 minutes until cheese melts and burger cooked medium-well.
- Assemble the Burger: Spread a generous amount of the signature spread on the bottom and top bun. Layer shredded lettuce, a tomato slice, grilled onions (optional), and the hot cheeseburger patty between.
- Serve Immediately: Wrap in parchment paper or serve open-faced on a burger board with sides if desired.
Notes
- For a 'Double-Double', simply double the patties and cheese per burger.
- If you're short on time, a food processor can chop onions finely for quicker caramelization.
- Swap beef for plant-based patties for a vegetarian version—Impossible Burger works well.
Nutrition
Your questions, answered
What internal temperature should the patty reach?
Ground beef should hit 160°F (71°C) internal temperature. Because this is a smash-style thin patty, it reaches that temperature quickly — usually within 2–3 minutes per side on a properly preheated pan, so a quick-read thermometer is worth using the first time you make it.
Can I use a regular skillet instead of cast iron?
Yes — stainless steel works well and gets hot enough for a good crust. Avoid non-stick pans for this; they can’t handle the high heat needed for the Maillard reaction, and the crust is the whole point of the smash technique.
Do I need to season the beef before smashing?
Season the top of the ball right after it hits the pan, before you smash — not before. Salting ground beef too early draws out moisture and can make the patty slightly dense.
Can I make this with a plant-based patty?
Yes, and the smash technique works with most plant-based patties that are sold as raw, moldable rounds (like Impossible Burger). Follow the package’s recommended internal temperature, which is typically 160°F (71°C) as well.
How do I keep the spread from making the bun soggy if I’m feeding a crowd?
Toast the buns and apply the spread no more than a few minutes before serving. If you’re staging burgers for a group, keep the spread in a bowl on the side and let people add it themselves — it takes 10 seconds and solves the problem entirely.
Is there a way to make a double patty version with this recipe?
Yes — smash and cook two thinner patties separately, then stack them with a slice of cheese between each patty while both are still in the pan. The residual heat from the bottom patty helps melt the inner cheese layer without overcooking either patty.