Warm olive oil in a medium saucepan. Add rice and onion. Stir until rice is well coated and translucent around edges, about 2 minutes. Add water and salt. Stir, cover, reduce heat to low and cook 20 minutes. Remove from heat and let rest, covered, for 5 minutes. Fluff rice. Then gently mix in remaining ingredients.
Recipe courtesy Guy Fieri, 2008