Quick Recipe Version (TL;DR)
Quick Ingredients
- 2 large yellow onions, thinly sliced
- 2 tablespoons unsalted butter (for onions)
- 1 tablespoon neutral oil (canola or vegetable, for onions)
- 1/2 teaspoon kosher salt (for onions)
- 1 teaspoon granulated sugar (optional, speeds browning)
- 2 tablespoons water (as needed, to deglaze)
- 1/2 cup mayonnaise
- 2 tablespoons ketchup
- 1 tablespoon yellow mustard
- 2 tablespoons dill pickle relish
- 1 teaspoon distilled white vinegar
- 1/2 teaspoon paprika
- 1/4 teaspoon garlic powder
- 1/4 teaspoon onion powder
- 1/8 teaspoon black pepper
- 1 pound (453 g) 80/20 ground beef
- 1 1/4 teaspoons kosher salt (for patties)
- 1/2 teaspoon black pepper (for patties)
- 8 slices American cheese
- 8 slices soft white sandwich bread (or brioche-style sandwich bread)
- 4 tablespoons unsalted butter, softened (for toasting bread)
Do This
- 1. Caramelize onions in butter + oil over medium-low heat, 25–30 minutes; season and deglaze with splashes of water as needed.
- 2. Stir together the “stacker”-style sauce; refrigerate while you cook.
- 3. Divide beef into 8 portions (2 oz each) and press into very thin patties; season with salt and pepper.
- 4. Cook patties on a hot skillet or griddle (medium-high), about 2 minutes per side, to 160°F (71°C).
- 5. Butter one side of each bread slice; toast in a skillet until golden.
- 6. Assemble: bread, cheese, two patties, caramelized onions, sauce, cheese, bread.
- 7. Grill assembled sandwiches on medium heat 2–3 minutes per side until deep golden and melty.
Why You’ll Love This Recipe
- Big Whopper-inspired flavor in a classic patty-melt format: toasted bread, melty American cheese, and savory beef.
- Caramelized onions add deep, sweet-savory richness that makes the whole sandwich taste “restaurant-level.”
- The tangy “stacker”-style sauce is quick to mix and hits that familiar fast-food vibe.
- Everything cooks in one skillet or on one griddle, so cleanup stays manageable.
Grocery List
- Produce: 2 large yellow onions
- Dairy: unsalted butter, 8 slices American cheese, mayonnaise
- Meat: 1 lb (453 g) 80/20 ground beef
- Bakery: 8 slices soft white sandwich bread (or brioche-style sandwich bread)
- Pantry: neutral oil (canola/vegetable), ketchup, yellow mustard, dill pickle relish, distilled white vinegar, paprika, garlic powder, onion powder, kosher salt, black pepper, granulated sugar (optional)
Full Ingredients
Caramelized Onions
- 2 large yellow onions (about 1 1/2 lb / 680 g total), halved and thinly sliced
- 2 tablespoons unsalted butter
- 1 tablespoon neutral oil (canola or vegetable)
- 1/2 teaspoon kosher salt
- 1 teaspoon granulated sugar (optional)
- 2 tablespoons water, plus more as needed (for deglazing)
Tangy “Stacker”-Style Sauce
- 1/2 cup (120 g) mayonnaise
- 2 tablespoons (30 g) ketchup
- 1 tablespoon (15 g) yellow mustard
- 2 tablespoons (30 g) dill pickle relish
- 1 teaspoon distilled white vinegar
- 1/2 teaspoon paprika
- 1/4 teaspoon garlic powder
- 1/4 teaspoon onion powder
- 1/8 teaspoon black pepper
- 1/8 teaspoon kosher salt
Thin Patties
- 1 pound (453 g) 80/20 ground beef
- 1 1/4 teaspoons kosher salt
- 1/2 teaspoon black pepper
Sandwich Assembly
- 8 slices soft white sandwich bread (or brioche-style sandwich bread)
- 4 tablespoons unsalted butter, softened (for toasting bread)
- 8 slices American cheese
Step-by-Step Instructions
Step 1: Caramelize the onions low and slow
Heat a large skillet (cast iron or stainless steel works best) over medium-low heat. Add 2 tablespoons butter and 1 tablespoon oil. Once melted, add the sliced onions and 1/2 teaspoon kosher salt. Stir to coat.
Cook, stirring every 3–5 minutes, until the onions turn deeply golden-brown and very soft, about 25–30 minutes. If you’d like to speed browning slightly, sprinkle in the 1 teaspoon sugar after 10 minutes.
If the onions start sticking or browning too quickly in spots, add 1–2 teaspoons water at a time and scrape up the browned bits. When finished, transfer onions to a bowl and cover to keep warm.
Step 2: Mix the tangy “stacker”-style sauce
In a small bowl, whisk together: 1/2 cup mayonnaise, 2 tablespoons ketchup, 1 tablespoon yellow mustard, 2 tablespoons dill pickle relish, 1 teaspoon white vinegar, 1/2 teaspoon paprika, 1/4 teaspoon garlic powder, 1/4 teaspoon onion powder, 1/8 teaspoon black pepper, and 1/8 teaspoon kosher salt.
Refrigerate until needed (even 10 minutes helps the flavor settle).
Step 3: Portion and press ultra-thin patties
Divide 1 pound ground beef into 8 equal portions (about 2 oz / 57 g each). Roll each into a loose ball, then press into a patty about 4 to 4 1/2 inches wide and very thin (aim for roughly 1/4 inch thick). Thin patties cook fast and give you that diner/fast-food melt vibe.
Season both sides of all patties with the 1 1/4 teaspoons kosher salt and 1/2 teaspoon black pepper.
Step 4: Cook the patties on a hot skillet or griddle
Wipe out the onion skillet if it’s heavily browned, or use a second skillet/griddle. Heat over medium-high heat until very hot, about 2 minutes. (If the pan is dry and your beef is leaner than 80/20, add 1 teaspoon oil.)
Cook patties in batches so you don’t crowd the pan. Cook for 2 minutes on the first side, flip, then cook 1–2 minutes more, until browned and cooked through to an internal temperature of 160°F (71°C).
Transfer patties to a plate. You’ll stack them in pairs for each sandwich.
Step 5: Butter-toast the bread until deeply golden
Spread 4 tablespoons softened butter evenly over one side of each bread slice (this is the side that will hit the skillet).
Heat a clean skillet or griddle over medium heat. Toast bread in batches, butter-side down, until golden, about 2–3 minutes. Flip and toast the second side for 30–60 seconds (this helps warm the bread without over-browning). Set toasted slices aside.
Step 6: Build the Whopper Melt-style stacks
For each sandwich, place one slice of toasted bread on your work surface. Add:
- 1 slice American cheese
- 2 thin patties
- A generous heap of caramelized onions (about 1/2 cup)
- 1 1/2 tablespoons sauce (spread it across the onions/patties)
- 1 slice American cheese
Top with the second slice of bread. Repeat for all sandwiches.
Step 7: Grill the assembled sandwiches until melty and crisp
Return the skillet to medium heat. Place sandwiches in the pan (work in batches). Cook 2–3 minutes per side, pressing gently with a spatula, until the bread is deep golden and the cheese is fully melted.
If your cheese needs help melting, lower heat to medium-low and cover the pan for 1 minute to trap heat.
Rest each sandwich for 2 minutes, then cut in half and serve warm.
Pro Tips
- For the thinnest patties: Press the beef between two pieces of parchment paper using a skillet bottom, then peel and cook.
- Don’t rush the onions: True caramelization takes 25–30 minutes. If you crank the heat, you’ll get sautéed onions instead of deep sweetness.
- Manage heat during the final grill: If the bread is browning faster than the cheese melts, drop to medium-low and cover briefly.
- Keep patties juicy: Cook quickly on medium-high and avoid pressing them down while cooking (pressing squeezes out moisture).
- Make it taste “fast-food” on purpose: American cheese is key here; it melts smoothly and gives the classic flavor.
Variations
- Extra Whopper vibe: Add 8 pickle chips (2 per sandwich) and a thin slice of tomato, and swap the bread for seeded burger buns toasted cut-side (you’ll lose the patty-melt shape but keep the flavor).
- Spicy version: Stir 1 teaspoon hot sauce or 1/4 teaspoon cayenne into the sauce, and add sliced pickled jalapeños.
- Smoky bacon melt: Add 2 slices cooked bacon per sandwich and use smoked paprika in the sauce (or increase paprika to 1 teaspoon).
Storage & Make-Ahead
Best fresh: Patty melts are at their peak right after grilling (crispy bread, fully melty cheese).
Make-ahead: You can caramelize the onions up to 4 days ahead and refrigerate in an airtight container. The sauce can be made up to 5 days ahead and refrigerated.
Leftovers: Store fully cooked sandwiches wrapped tightly and refrigerated up to 2 days. Reheat in a skillet over medium-low heat for 3–5 minutes per side until hot throughout. (Microwaving works, but the bread will soften.)
Nutrition (per serving)
Approximate, per 1 sandwich: 820 calories, 46 g protein, 55 g fat, 40 g carbohydrates, 6 g sugar, 5 g fiber, 1650 mg sodium.
