Heat the oil in a large, heavy-bottomed skillet or saucepan over medium-high heat. Add the dry, unrinsed rice and stir it around constantly for about 3 to 4 minutes until you hear a gentle crackling sound and the grains turn a light golden color similar to raw almonds. This step builds a nutty, deep flavor foundation and prevents mushy rice.

Add the diced onion directly to the toasted rice and stir together for another 2 minutes until the onion softens and turns translucent. Toss in the minced garlic and cook for 30 more seconds until fragrant.

Pour in the tomato sauce, cumin, chili powder, and salt. Stir everything together and let it cook for about 1 to 2 minutes so the spices bloom in the oil and the tomato sauce thickens slightly around the rice. The mixture should deepen to a rich, brick-red orange color.

Pour in the chicken broth and stir gently to combine. Bring everything to a boil, then immediately reduce the heat to low. Scatter the peas and carrots over the top if using without stirring them in. Place a tight-fitting lid on the pan and let the rice cook undisturbed for 18 minutes. After 18 minutes, remove from heat and let it rest, still covered, for 5 minutes.

Remove the lid and use a fork to gently fluff the rice from the edges inward. Taste and adjust salt if needed, then scatter fresh cilantro on top and serve immediately.