Cook Morningstar Farms Spicy Black Bean Veggie Burgers according to package directions. Cut into bite-size pieces. Brush olive oil over bread shell pizza crusts. Sprinkle with cumin. Top with cheddar cheese. Divide burger pieces, tomato slices, queso fresco cheese and green onions among shells. In covered grill place bread shells on rack directly over medium heat. Cover and grill about 6 minutes or until cheddar cheese melts and pizza is heated through. Cut each into quarters. Sprinkle with cilantro. Serve with salsa and sour cream, if desired. *NOTE: Queso fresco is a mild cow's milk cheese that crumbles. Queso quesadilla is a mild white cheese that melts easily. Both are found in supermarkets or Mexican groceries.