Heat 3 tablespoons of vegetable oil in a large saucepan over medium-low heat.
Add 2/3 cup of diced onions to the pan and sauté until golden.
Add 1 1/2 cups of uncooked white rice to the pan and stir to coat the grains with oil.
Mix in 1 cup of chopped green bell pepper, 1 teaspoon of ground cumin, and 1 teaspoon of chili powder.
Stir in 1 1/2 cans of tomato sauce, 2 teaspoons of salt, 1 minced garlic clove, and 1/8 teaspoon of powdered saffron.
Pour in 3 cups of water and mix well.
Cover the saucepan, bring the mixture to a boil, and then reduce the heat to a simmer.
Cook for 30 to 40 minutes, or until the rice is tender, stirring occasionally.