Form ground chuck into 1/4 pound patties. Cover and chill until ready to use. (TIP: Cover a large platter with plastic wrap. Place patties on platter. Cover patties with plastic wrap. When ready to cook, place patties on grill and discard all plastic wrap from patter. Presto! a clean plate for grilled burgers.)

In large pan, heat 1 tablespoon oil over medium heat. Add onion and mushrooms.

Season with salt to taste. (TIP: It is important to season onions and mushrooms as they cook to get the most flavor out of them)

Saute until starting to caramelize, 10 -15 minutes stirring often.

Turn down heat if starting to burn. Remove from heat and allow to cool.

To prepare burgers: use your thumb to make a depression in center of all patties. Season both sides with Weber Montana seasonings.

Cut 8 slices of provolone into a 2 1/2 inch circles and place a piece on 4 patties.

Place 1 1/2 tablespoon of onion / mushroom mixture on top of cheese.

Place remaining cheese circles on top of onion / mushroom mix.

Top with the remaining four patties on top of stuffed patties. Press to seal together. Chill for 1 hour before grilling.

Remove hamburgers from fridge. Clean grill and heat to medium high.

Grill burgers 5 -8 minutes, per side, to desired temperature.

Top burgers with 4-5 slices of banana peppers.

Top each burger with 1 slice of provolone cheese.

Cook until cheese melts. Allow burger to rest for 5 minutes.

As burgers rest, brush buns lightly with melted butter. Grill cut side down until slightly toasted

To serve, spread 1 teaspoon of mayo on toasted bun.

Add burger and top with remaining onion / mushroom mix.