In a mesh strainer, thoroughly rinse the rice and set aside.
Set the Instant Pot to sauté. Add the oil, garlic, and onion. Sauté briefly until the onions are translucent. Cancel the sauté function and add the tomato paste. Sauté briefly (the bottom of the pot will still be hot).
Add the chicken stock and use a rubber spatula or wooden spoon to scrape up everything sticking to the bottom of the pot. Add the cumin and salt. Add the rinsed rice; do not stir.
Close the lid and set the Instant Pot to low pressure at 5 minutes. Do not use the “keep warm” function.
When the 5 minutes are up, let the pressure come down naturally while you make your tacos/enchiladas/fajitas/margaritas/queso/guacamole/what have you. It will take about 20 minutes. When the little metal pressure stopper drops, you can open the lid and stir the rice gently to disperse the onions throughout.