Place chicken broth, onion, garlic, oregano, salt, and tomatoes in a blender.
Purée until smooth. Add more chicken broth if needed so you end up with 4 cups of liquid.
In a large saucepan heat oil over medium heat.
Add rice and sauté until light golden brown.
Add tomato purée to the saucepan and stir to combine with rice.
Increase heat and bring to a boil.
Cover saucepan and reduce heat to low.
Cook, covered over low heat for 20 minutes.
After 20 minutes, turn off heat and allow rice to sit for 10 minutes. No peeking!
After 10 minutes, remove lid and fluff rice with a fork to serve.
Taste and season with additional salt if needed.