My friend owns a Mexican restaurant and I could never get authentic Mexican rice just right until she taught me how. Add a tablespoon of vegetable oil to a sauce pan, and saute one cup of dry rice for a minute or two. Add 1 and 3/4 cups of water, 2 tablespoons of tomato paste, 1 tsp. of cumin, and 1/2 tsp of salt. Stir and bring to the boil. Cover, and cut heat to the lowest flame. Let it simmer for 15 min. Fluff with a fork. Perfect Mexican rice.
Do not try to substitute any other tomato product.....it just won't work.
BTW, I buy tomato paste in a tube rather than by the can. It's always ready for this recipe, and others, in the fridge without opening a whole can.