In a large skillet, cook beef and onion over medium heat until the meat is no longer pink, 3-5 minutes, breaking into crumbles. Drain. Stir in the pizza sauce, mushrooms, sugar and oregano; mix well. Spoon onto buns; sprinkle with mozzarella cheese.

Place on ungreased baking sheets. Broil 4 in. from the heat until cheese is melted, 2 minutes.

To freeze for quick lunches later, place the split and toasted buns on a baking sheet. Spoon the meat mixture onto buns; freeze for 1 hour. Transfer to freezer-safe airtight containers.

To use frozen burgers: Thaw completely in the refrigerator. Sprinkle with cheese. Broil 4 in. from the heat until heated through and cheese is melted, 2 minutes.

Nutrition Facts

each: 205 calories, 8g fat (4g saturated fat), 36mg cholesterol, 357mg sodium, 15g carbohydrate (4g sugars, 1g fiber), 16g protein.