This is how we Mexicans from California make our rice. We call it Spanish rice, not mexican rice! I didn't hear the term "mexican rice" until I moved to the midwest. This is how all of my family make the rice, aunts and grandmother alike. We don't put in peas or carrots like I have seen from other recipes. I was told by my sons girlfriend that I make it just like the restaurants. I hope that was a compliment!!
You want to make rice in a heavy bottomed fryin pan and have a tight fitting glass lid. Place cooking oil in pan with raw rice, use a medium heat to brown the rice, then add the onion making sure all rice/onion is coated with oil. When rice has turned white you add the 1/2 can of tomato sauce, it should be sizzling by this time.
When the rice and tomato sauce are sizzling, you add the 2 cups of water and all the spices, stirring until well mixed. When rice mixture is bubbling you lower the heat to simmer, covering with glass lid. cook on low heat for 15 minutes. DO NOT LIFT LID!!!
When the 15 minutes are completed, turn off heat and let sit for 5 minutes. Remove lid and use spatula to turn rice from bottom to top. Rice is done and ready to eat!
As you can see the rice should be dry...not sticky(too much water) or gummy(someone lifted the lid)Not bright red(whole can of tomato sauce)or almost white(too little tomato sauce)there is also no brown onions or brown rice(browned too long)