→ Bread
01 -
8 slices hearty sandwich bread (sourdough, whole wheat, or artisan)
02 -
2 tablespoons unsalted butter
→ Vegetables and Aromatics
03 -
1 tablespoon olive oil
04 -
1 small onion, thinly sliced (optional)
05 -
8 ounces mushrooms, sliced (cremini, white, or baby bella)
06 -
1 garlic clove, minced
→ Seasonings
07 -
Salt, to taste
08 -
Black pepper, to taste
09 -
1 teaspoon fresh thyme or ½ teaspoon dried thyme (optional)
→ Cheese and Condiments
10 -
4 to 6 slices Swiss cheese
11 -
1 teaspoon Dijon mustard (optional)