Cook the cavatappi: Boil salted water and cook the pasta until just tender. Drain and save a little pasta water.
Brown the sausage: Heat a large skillet over medium heat. Add the sliced andouille sausage and cook until lightly browned around the edges. Remove and set aside.
Cook the shrimp: Add the shrimp to the same skillet and cook until opaque and just cooked through. Remove quickly so it stays tender.
Sauté the vegetables: Add the bell pepper and red onion. Cook until slightly softened. Add the diced tomato near the end and cook briefly.
Start the cheese sauce: Melt the butter in a saucepan over medium heat. Whisk in the flour and cook for about 30 seconds.
Add the milk: Slowly pour in the milk while whisking. Keep stirring until the mixture starts to thicken.
Melt in the cheese: Lower the heat and gradually stir in the cheddar and Monterey Jack until the sauce is smooth.
Season the sauce: Add black pepper and a little Creole seasoning. Taste before adding salt because the cheese and sausage already contain salt.
Combine the pasta: Add the cooked cavatappi to the cheese sauce and stir until evenly coated.
Add the filling: Fold in the sausage, shrimp, peppers, onion, and tomatoes. Add a small splash of pasta water if the sauce feels too thick.
Make the breadcrumbs: Melt butter in a small skillet. Add breadcrumbs and chili seasoning. Stir until golden and crisp.
Finish the dish: Spoon the creamy pasta into bowls and sprinkle the chili-butter breadcrumbs over the top while they are still crisp.
