Burger King Mushroom Swiss Melt (Shroom n' Swiss) Recipe

Burger King's Shroom n' Swiss Melt is two 2-ounce beef patties with Swiss cheese, sautéed mushrooms and Stacker sauce between two slices of toasted bread. This copy browns eight ounces of sliced mushrooms in butter, cooks eight thin patties two minutes a side, melts a slice of Swiss on each and stacks them on buttered, toasted bread. It makes four melts in 35 minutes.

What is on Burger King's Shroom n' Swiss Melt

Burger King announced the Shroom n' Swiss Melt on 29 November 2023 as the new member of its BK Melts line, on sale from 7 December for a limited time. The release lists what is in it: two slices of toasted bread, two flame-grilled Whopper Jr. patties, Swiss cheese, sautéed mushrooms and Stacker Sauce. A footnote gives the size of the patties, 2 ounces each before cooking, a quarter pound per melt.

The two melts that returned with it, the Classic and the Bacon, carry American cheese and caramelized onions where this one has Swiss and mushrooms. The recipe here is a reconstruction from that description, not Burger King's formula, and MakeFoodLovely is not connected with Burger King.

Recipe

Burger King Shroom n' Swiss Melt

A reconstruction of Burger King's Shroom n' Swiss Melt — two 2-ounce beef patties, Swiss cheese, sautéed mushrooms and Stacker sauce between two slices of toasted bread. Four melts.

5.0 (1)Print

Prep

15 min

Cook

20 min

Total

35 min

Serves

4

Cuisine

American

Ingredients

• For the Stacker sauce:
• 1/4 cup mayonnaise
• 1 tablespoon ketchup
• 1 1/2 teaspoons sweet pickle relish
• 1/2 teaspoon yellow mustard
• 1/2 teaspoon Worcestershire sauce
• 1/4 teaspoon smoked paprika
• 1/4 teaspoon garlic powder
• For the mushrooms:
• 1 tablespoon unsalted butter
• 8 ounces white mushrooms, sliced 1/4 inch thick
• 1/4 teaspoon salt
• For the melts:
• 1 pound ground beef (80% lean)
• 1/2 teaspoon salt
• 1/4 teaspoon black pepper
• 8 slices Swiss cheese
• 8 slices white sandwich bread
• 2 tablespoons unsalted butter, softened

Instructions

1. Stir the mayonnaise, ketchup, relish, mustard, Worcestershire sauce, smoked paprika and garlic powder together. Refrigerate the sauce while the rest is cooked.
2. Melt 1 tablespoon of butter in a large skillet over medium-high heat. Add the mushrooms in one layer and cook for 6 to 8 minutes, stirring only two or three times, until their liquid has cooked off and they are browned. Stir in 1/4 teaspoon of salt and tip them into a bowl.
3. Divide the beef into 8 portions of 2 ounces and press each into a patty about 4 inches across. Season both sides with 1/2 teaspoon of salt and the pepper.
4. Wipe out the skillet and set it over medium-high heat. Cook the patties in two batches for 2 minutes a side, until browned and 160°F inside. Lay a slice of Swiss cheese on each patty for the last 30 seconds.
5. Spread the softened butter on one side of each slice of bread. Toast the slices, buttered side down, in a clean skillet over medium heat for about 2 minutes, until golden.
6. Spread 1 tablespoon of sauce on the untoasted side of 4 slices. Stack two cheese-topped patties on each, divide the mushrooms over them and close with the remaining bread, toasted side out.

Nutrition

Calories:

800

Calculated from the ingredient quantities above using the USDA FoodData Central database, then divided by the number of servings. It is an estimate and will vary with the exact products you use.

Stacker sauce, not Royal sauce

Burger King's release names Stacker Sauce for all three melts. Royal Sauce is a different one: according to Daily Meal, it replaced King's Sauce in 2017 and goes on the Royal Crispy Chicken sandwiches and wraps.

The sauce in the card is a half batch of this site's Stacker sauce, cut down to seven ingredients. The full recipe keeps for a week in the refrigerator, so making all of it and saving the rest is the easier route.

Browning the mushrooms

• One layer, high heat. Mushrooms are mostly water. Crowded in the pan they steam and stay pale; spread out, the water cooks off and they brown.
• Leave them alone. Constant stirring keeps them from colouring. Two or three turns in eight minutes are enough.
• Salt at the end. Salt draws the water out early and slows the browning.
• Quarter-inch slices. Thinner ones shrivel to almost nothing; thicker ones slide out of the sandwich.

Cremini mushrooms cook the same way and come out a shade darker.

Bread and patties for a mushroom Swiss melt

The release says toasted bread and nothing more. Soft white sandwich bread, buttered and toasted on one side only, stays crisp outside and soft inside, where the sauce goes. Sourdough works too. Thick-cut Texas toast makes a melt that is hard to bite through.

The patties are thin on purpose. At 2 ounces they cook in four minutes, and two of them carry two slices of cheese where one thick patty would carry one. The release calls them flame-grilled; a grill does that at home, and so does a very hot cast-iron skillet, which is what the card uses.

The other BK Melts

The Classic Melt and the Bacon Melt use the same bread, patties and sauce. For the Classic Melt, replace the Swiss with American cheese and the mushrooms with caramelized onions. The Bacon Melt adds crisp bacon to that, and its page covers the Classic Melt as well. For a Burger King sandwich on a bun, see the bacon cheeseburger.

Making it ahead

The sauce and the mushrooms keep for three days in the refrigerator; warm the mushrooms in a dry skillet before assembling. Patties this thin dry out when reheated, and an assembled melt goes soft within the hour, so cook and stack them just before eating.