-
1
In a large nonstick skillet, add 2 tablespoons butter and melt over medium-low heat.
-
2
Add onions and cook for 15 minutes, stirring occasionally, or until onions just begin to caramelize.
-
3
After 15 minutes, add sliced mushrooms and continue to cook until mushrooms are tender and onions are brown and caramelized, about 10 more minutes.
-
4
Season with salt and black pepper.
-
5
Transfer onions and mushrooms to a bowl and set aside.
-
6
Place skillet back on stove and turn heat to medium.
-
7
There should be enough fat left in pan to cook veggie patties, but if it seems too dry, spray pan with nonstick spray.
-
8
Once pan is hot, add veggie burgers.
-
9
Cook according to package instructions, usually about 67 minutes per side or until completely cooked through.
-
10
Remove from heat.
-
11
Assemble sandwiches by placing 1 slice cheese on bottom slices of rye bread.
-
12
Top each one with a handful of arugula and place veggie burgers on top.
-
13
Top veggie burgers with caramelized onions and mushrooms, and then place another slice of provolone cheese.
-
14
Place remaining slices of rye bread on top.
-
15
Preheat a griddle pan or large nonstick skillet over medium heat.
-
16
Add remaining 2 tablespoons butter and cook sandwiches in batches.
-
17
Cook sandwiches for about 34 minutes each side or until brown on each side, adding more butter if needed.
-
18
Serve immediately and enjoy!
