Spray a Large Crockpot (6qt or larger) with non-stick spray
In a medium skillet over medium-high heat, brown the ground beef or chicken or turkey with the onion, garlic, pepperoni and green bell pepper. Drain any excess fat.
Rinse pasta and place in the crockpot with drained ground meat mix. Stir. Pour pasta sauce and 1 cup water over noodle mix.
Top with shredded mozzarella.
Cover and cook on low for 5-6 hours (no not lift the lid).