In a large soup kettle, simmer chicken breasts in 2 cups of water (or chicken broth). Add onion to chicken as it simmers. While it's cooking, you can slice other vegetables. When chicken is cooked throughout, remove and set aside.
Add tomatoes, potatoes, carrots, peppers and spices to onion and broth mixture. Continue to simmer.
Break chicken into chunks, de-bone and add to stew. Simmer 30 minutes, or until carrots and potatoes are done. Add rice and simmer 10 more minutes. Makes about 8 servings.