Saute onion in one tablespoon oil. Peel sweet potatoes and cut into 1 cm cubes. Add remaining one tablespoon of oil and potatoes to onions, and saute for 5 miknutes. Add rice and saute for 2 minutes. Add vegetable broth and pepper. Bring to a boil, cover and reduce heat. Simmer until liquid is absorbed, about 40 to 45 minutes. Serve warm, or chill and serve cold. Per serving: 238 cal; 4 g prot; 150 mg sod; 44 g carb; 5 g fat; 0 mg chol; 44 mg calcium