'Calabacitas Guisada' (Stewed Mexican Zucchini)

Heat the vegetable oil in a saucepan over medium heat; cook the onion and garlic in the hot oil until soft about 5 minutes. Add the zucchini slices and stewed tomatoes and stir gently. Cover and cook until the zucchini is tender 8 to 10 minutes. Remove from heat season with salt and add the Cheddar cheese; allow to sit until the cheese has melted.