Heat the vegetable oil in a large, heavy-bottomed skillet over medium heat.

Add the chopped onion and cook, stirring occasionally, until it is soft and translucent, about 5 minutes.

Add the uncooked rice to the skillet and cook, stirring frequently, until the rice starts to turn a light golden brown.

Pour in the chicken stock and salsa. Stir well to combine.

Reduce the heat to low, cover the skillet, and let it simmer until all the liquid has been absorbed by the rice, about 15-20 minutes.

Remove the skillet from the heat and let it stand, covered, for 5 minutes. Fluff the rice with a fork before serving.