Heat oil in medium saucepot over medium-high heat. Add onions; cook until soft and translucent, about 5 minutes. Add rice and garlic. Cook, stirring frequently, until rice is coated in oil and garlic is fragrant, about 4 minutes more.
Add chicken bouillon mixture, tomato sauce and Adobo to pot, stir to combine. Bring rice mixture to boil; reduce heat to low. Simmer, covered, until water is absorbed, about 20 minutes, adding peas to pot after 15 minutes. Remove pot from heat. Let sit, covered, until rice is tender, about 5 minutes more.
Using fork, fluff rice. Serve immediately.