• Place chicken in a crockpot.
• Add water and salt and pepper for flavoring.
• Cover and cook for 4 hours on high or 6-8 hours on high.

To make sauce and and assemble casserole

• Take chicken breasts out of the crockpot to cool for cutting.
• Save the chicken broth to use later.
• Finely dice and saute onions until translucent, in a dutch oven.
• Cut up Velveeta into cubes and add to onions once cooked.
• Stir in tomatoes, and soup.
• Stir all together, watching cheese sauce so it doesn't burn.
• Meanwhile, boil the rigatoni noodles in salted water or chicken broth.
• Cut up chicken into cubes or shred.
• Add chicken and 1/2 - 1 cup chicken broth to the sauce.
• Stir together.
• Drain noodles and add to the cheese sauce.
• Gently stir everything together.
• Pour into casserole dish.
• Sprinkle cheese across top.
• Cover with foil.
• Bake for 20 minutes, at 350, then remove foil and cook for 10 more minutes. - or - Store in refrigerator or freezer.
• If cooking from cold, cook for 30 minutes with foil on, and then remove the foil and cook for 15 minutes.