Cut chicken into bite-sized pieces, coat with 1 - 1.5 tablespoons of ranch seasoning. Saute in a skillet with 1 tablespoon of bacon grease along with bell peppers and onion. Cook till chicken is no longer pink.
Combine Alfredo sauce, evaporated milk and milk with the partially cooked pasta. Stir in one teaspoon of ranch seasoning.
Begin layering casserole in the casserole crock pot with half the pasta and sauce combination. Then layer ½ of each of the following chicken and tomatoes. Use ⅓ of the fried bacon. Spread 1 cup of cheese over top and repeat one more time.
After the cheese the second time, cover with 1 cup of cheese and remaining bacon.
Cook on low for 2-3 hours till casserole cooked through and cheese is melted on top.