Preheat the oven to 375℉. Cook the Rigatoni pasta per the directions listed on the box. In a large pot, bring the water to a boil, and season with salt to taste. Add oil to keep the pasta from sticking together.
Add unsalted butter. Then add the onions, then add the diced bell peppers and cook. Immediately stir until it starts to become lumpy, then slowly add the carnation milk (about half a cup at a time) while stirring or whisking.
Once you have added the milk and cheese, add the pasta water, and season with the Jacmel seasoning, Saint-Marc, and salt to taste. Reduce the heat to medium-low. Allow the roux to cook. Stir occasionally.
Once the roux has thickened, drain the cold water from the pasta. Place the rigatoni pasta in a large bowl, then add the roux. Stir well to combine, then add mozzarella cheese to the macaroni. Continue to mix well.
Layer the pasta onto a baking sheet or cast iron skillet, and top with the handful of cheddar cheese, mozzarella cheese, and parmesan cheese. Repeat the steps. Bake until golden brown.