Heat broiler to high with rack at medium height. Beat eggs, salt and pepper until well blended.
Spray an oven-safe skillet with oil and heat over medium-high. Brown the chorizo (in order to do this, you must remove the casing). Add the corn and tomatoes and simmer for about four minutes. Reduce heat to medium and add the egg mixture, ensuring it evenly coats the bottom of the pan and that vegetables are evenly distributed. Lift the edges of the frittata to ensure all egg gets heated. Cook until only the top of the mixture is liquidy.
Place the pan under the broiler until surface is puffed and lightly browned, about 2-4 minutes. Remove from oven. Sprinkle with cheese and cover and let sit for about five minutes, or until cheese is melted. Sprinkle fresh cilantro over the top. Serve hot.