This is an authentic Mexican-style rice recipe done in an authentic American way. It's just how it would be made in almost all California Mexican restaurants and can easily be replicated at home.
Heat the oil in a saucepan with a lid, when hot, add the rice and the onion. Sauté until the rice just begins to turn opaque, about 5 minutes; add the tomato sauce and broth or water, along with about ½ teaspoon salt. Stir, cover, lower the heat, and cook for 25 minutes, or until the liquid is absorbed (don’t peek, just let it cook); uncover, fluff with a fork, taste and adjust salt. Top with Cotia cheese, if desired. Serve immediately.