Heat oil in a medium saucepan over medium high heat. Cook onions and bell peppers until lightly browned and tender, stirring in garlic when almost done to prevent burning. Stir in tomatoes, vegetable stock, pepper, and chili powder.
Add to VitaClay cooker
Stir in rice, cover, and cook on fast/stew for 40 minutes - 1 hour.
Stir in peanut butter until well blended, and serve.