→ Meats
01 - 1 pound ground beef, 80/20 lean-to-fat ratio preferred
→ Vegetables
02 - 1 medium yellow onion, finely diced
03 - 1 green bell pepper, finely diced
04 - 1 small red bell pepper, finely diced
05 - 2 cloves garlic, minced
→ Sauces and Liquids
06 - 2 tablespoons ketchup
07 - 1 tablespoon Worcestershire sauce
08 - 1 cup beef broth
09 - 2 teaspoons yellow mustard
→ Spices and Seasonings
10 - 1 teaspoon smoked paprika
11 - 1/2 teaspoon sea salt, plus more to taste
12 - 1/2 teaspoon black pepper
13 - 1/4 teaspoon chili flakes, optional
→ Cheese
14 - 1 1/2 cups shredded provolone cheese
15 - 1/2 cup shredded mozzarella cheese
→ Bread
16 - 4 brioche burger buns, split and lightly toasted
17 - 2 tablespoons unsalted butter, for toasting buns