Heat the olive oil in a heavy pot or caldero over medium heat. Cook the sofrito for 2 to 3 minutes until fragrant.
Stir in the tomato sauce and sazón; cook 1 minute more.
Add the pigeon peas, olives and capers; stir to coat.
Add the rice, water or broth, adobo and bay leaf. Stir once and bring to a boil.
Reduce the heat to low, cover tightly and steam for 25 minutes without lifting the lid.
Remove from the heat and rest, covered, for 5 minutes. Remove the bay leaf and fluff with a fork.
For pegao, return the uncovered pot to medium-low heat for 2 to 3 minutes until the bottom crisps, then scrape up the golden crust and serve.