Philly Cheese Steak-Stuffed Bell Peppers

Ingredients (8)

• + 3 large green bell peppers, halved lengthwise and seeded add to pantry
• + 1 (14 ounce) package thinly sliced frozen Philly beef steak add to pantry
• + 1 large sweet onion, diced add to pantry
• + 1 (6 ounce) package sliced baby bella mushrooms, diced add to pantry
• + 1 tablespoon olive oil add to pantry
• + 1 tablespoon minced garlic add to pantry
• + 1 teaspoon Montreal steak seasoning, or more to taste add to pantry
• ✓ 6 slices provolone cheese