In a 4 litre Dutch oven over medium-high heat, cook chicken in oil until chicken is lightly browned and no longer pink, stirring frequently. Add onion and garlic; cook and stir 3 to 4 minutes or until onion is tender. Add remaining ingredients except rice; mix well. Bring to a boil. Reduce heat to medium-low; cover and cook 30 minutes or until sweet potato is tender, stirring occasionally. If stew becomes too thick, add additional water. Serve stew over hot rice.