In a medium saucepan set over medium heat, melt together the olive oil and butter. Add the rice and stir to coat. Cook, stirring frequently, for about 2 to 3 minutes, until the rice is toasted.

Stir in the chicken broth, tomato sauce, chili powder, cumin, garlic salt, oregano, and diced tomatoes (if using). Increase the heat to high and bring to a boil, stirring occasionally. Stir well, reduce the heat to low, cover the pot with a lid, and cook at a gentle simmer for 20 minutes (or follow the instructions on the bag of rice). If the rice isn’t quite tender or the liquid isn’t absorbed after 20 minutes, replace the lid and cook for an additional 2 to 4 minutes. Remove from heat, leave the lid on, and allow the rice to rest for a few minutes. Fluff with a fork and serve.