If not using leftover rice, boil water and add dry rice. Reduce heat to low, cover, and cook for 20 minutes. This step can be done even up to 2-3 days in advance (and for some reason, fried rice tastes better when the rice is cold). Heat butter over medium heat and saute onions, carrots, and cabbage until carrots are tender. Add cooked rice, soy sauce, and seasoning to taste (you won't even come close to using all of it; save the rest for future fried rice or use as you would seasoning salt.)