Directions

1. Preheat an oven to 350 degrees F (175 degrees C).
2. Fill a large pot with lightly salted water and bring to a rolling boil over high heat. Once the water is boiling, stir in the rotini, and return to a boil. Cook uncovered, stirring occasionally, until the pasta has cooked through, but is still firm to the bite, about 8 minutes. Drain well in a colander set in the sink.
3. Place the cooked pasta into a large mixing bowl, and add the cream of mushroom soup, ketchup, green chiles, onion, and luncheon meat. Pour into a 9x13 inch baking dish, and evenly sprinkle with the Cheddar cheese.
4. Bake in the preheated oven until the casserole is hot and the Cheddar cheese has melted, about 10 minutes.