Preheat oven to 450°F. Line and grease rimmed cookie sheet. Process cauliflower into rice-sized pieces. Fry with olive oil for 10min. Cool. Combine all remaining ingredients except for tomatoes and last 1/2 cup cheddar. Form four flat mounds on baking sheet. Bake 10min, flip and make another 5min. Top with sliced tomato and grated cheddar. Bake another 3min.