Arroz con gandules is a combination of rice and pigeon peas cooked in the same pot with sofrito. This is Puerto Rico's national dish along with roasted pork. I make a whole pot of arroz con gandules at least once a month just for me. I eat it all week long with nothing but lots of hot sauce. This rice dish is a must for all family events, gatherings or even a day at the beach.
Rinse the rice with cold water, drain and set aside.
Heat the oil and sofrito in a 6-quart Dutch oven or caldero over medium-high heat, 2 minutes. Stir in the gandules with liquid, tomato sauce, olives, sazón, adobo and black pepper to taste then bring to a simmer. Stir in the rice, add 2 cups water and bring to a boil until the water begins to evaporate. Reduce the heat to low, cover and cook until the rice is tender, about 25 minutes. Remove from the heat and let sit for 20 minutes.
Before serving, fluff the rice and add the cilantro.
Do not stir the rice too much as it cooks to keep it from becoming sticky.