Step 1Heat the oil in a large deep skillet over medium heat. Add the onion, garlic, chile and cumin seeds and cook until the onion is tender, about 5 minutes. Add the tomatoes and cook until soft, about 5 minutes. Add the zucchini, corn, oregano and salt and cook, uncovered, until the zucchini is tender, stirring as needed, 10 to 12 minutes. Top evenly with the cheese and cook until the cheese is almost melted.