→ Meats
01 - 1 lb ground beef, 80/20 blend preferred
→ Vegetables & Aromatics
02 - 2 large yellow onions, thinly sliced
03 - 2 cloves garlic, minced
→ Dairy
04 - 4 slices provolone cheese (Swiss or Gruyère also suitable)
→ Breads
05 - 4 brioche buns or hamburger rolls
→ Liquids
06 - 1/2 cup low sodium beef broth
07 - 1 tablespoon Worcestershire sauce
→ Pantry & Spices
08 - 2 tablespoons unsalted butter
09 - 1 tablespoon olive oil
10 - 1 tablespoon all-purpose flour
11 - 1 teaspoon fresh thyme leaves or 1/2 teaspoon dried
12 - 1/2 teaspoon kosher salt, plus additional to taste
13 - 1/4 teaspoon black pepper, plus additional to taste