Rinse rice with a strainer thoroughly until stream of water is clear.
Add rinsed rice and chicken stock to Instant Pot liner and rest for at least an hour and no more than 6 hours. Do not turn on the Instant Pot.
Strain rice and keep the chicken stock.
Place empty insert into the Instant Pot and select Sauté. Add olive oil and when shimmering, add onions and sauté until soft and translucent (about two to three minutes). Add garlic and sauté for one minute.
Add rice, stir until grains are coated, and sauté for one minute.
Add tomatoes and sauté for one minute.
Add stock and better than bouillon and stir to incorporate everything.
Lock lid and select (Custom) Rice setting. Cook and allow pressure to naturally release.
Salt and pepper to taste.