Heat a medium saucepan over medium heat and add 2 tablespoons of vegetable oil, swirling to coat.
Once the oil shimmers, add 1 cup of long-grain white rice. Stir constantly for 5–7 minutes until the grains turn golden brown.
Add 0.5 cup of finely diced yellow onion and cook for 3–4 minutes until translucent.
Stir in 2 cloves of minced garlic and cook for 1 minute until fragrant.
Pour in 0.5 cup of tomato sauce and cook, stirring, for 2 minutes.
Carefully add 2 cups of low-sodium chicken broth, 0.5 teaspoon of salt, and 0.25 teaspoon of ground cumin. Stir to combine.
Bring to a rolling boil over medium-high heat, then reduce heat to low, cover tightly, and simmer without lifting the lid for 18–20 minutes.
If using, gently stir in 0.25 cup of frozen peas and carrots after turning off the heat.
Keep the lid on and let the rice rest for 5–10 minutes off the heat.
Remove the lid and fluff the rice gently with a fork. Serve warm.