Corn, black beans, and tomato stuffed pattypan squash    3 large pattypan squash  1 Tbsp olive oil  1 onion, diced  3 garlic cloves, minced  1 1/2 cups cooked black beans (or 1 can, drained and rinsed)  2 ears corn, kernels cut off  3 medium tomatoes, chopped  1 Tbsp cumin  1/2 tsp cayenne pepper  salt to taste  1/4 cup shredded mozzarella cheese