In the blender make a puree with the tomatoes, the onion and the garlic, I used to have ready my puree before start frying the rice, so when I need it, it is ready.

I prepare my rice almost always in a pan or in a saucepan, because it needs room to grow. There are some recipes that ask you to put the rice in warm water for 15 min. before you fry it. I don't do it, since I cook with little amount of oil, and when it is dry, there is no problem of having the rice stuck in the pan. So fry your rice uniformly until light golden, with medium low heat.

Add the puree and fry for few minutes, add salt, l l/2 cups of chicken stock, and parsley. Turn down the heat to the minimum and cover with the lid. Check it in 15 min, add the rest of the stock if the rice needs more liquid to cook. Don't stir with spoon, do it with a fork, this way you don't break the rice. It will be ready when the rice is soft and dry.

Optional: At the time you add the stock you may add one carrot chopped and some green peas, or some corn. If you used canned vegetables, just put them at the end to get warm.

Notes:
* It is better if you don't use precooked rice.
** It is a well known rule that you must use the double amount of liquid from the amount of rice, so if you do it with cups you can measure your liquids better.
*** I personally don't use lemon as I do with white rice, but there are some recipes that advice it, in this case it would be up to you.

If you want to keep the leftover for next day, keep it in a hermetic recipient, so it won't lose its humidity, when you want to reheat it again, do it in the microwave or bain marie.