Brown the meat by adding ground beef (or turkey) and diced onion to a skillet over medium heat. Cook for 6-8 minutes until browned; drain excess fat.

Combine browned meat mixture in the crock pot with chopped bell peppers, uncooked rice, diced tomatoes, beef broth, Italian seasoning, salt, and pepper. Mix well.

Set the crock pot to cook on low for 6-8 hours or high for 3-4 hours.

Check for doneness, ensuring rice is tender and absorbed most liquid. Stir to incorporate and adjust seasoning if needed.

Serve soup in bowls topped with shredded cheese, sour cream, or fresh herbs.