Mushroom and Provolone Patty Melts Recipe

Ingredients

• 1 pound ground sirloin
• Cooking spray
• 1 tablespoon olive oil
• 1/4 cup thinly sliced yellow onion
• 1/8 teaspoon salt
• 1/8 teaspoon black pepper
• 1 (8 ounce) package sliced cremini mushrooms
• 1 1/2 teaspoons all-purpose flour
• 1/4 cup dark beer (such as porter)
• 8 (1.1 ounce) slices rye bread
• 4 (3 / 4 ounce) slices reduced-fat provolone cheese