Start by adding the vegetable oil to the caldero or large pot and set the stove heat to medium. Toss in your chopped cured salted pork into the pot and cook until it is fried. Remove the cured salted pork and set aside but keep the grease in the caldero. 

Next, add your sofrito, tomato sauce, sazon culantro y achiote, cumin, spanish olives, and gandules to the caldero. Cook and stir the mixture for about 3 to 4 minutes. In addition, add your water and bring to boil. Rinse your medium grain rice to remove starch. 

Lastly, add your medium grain rice and the fried cured salted pork and stir everything gently. Place a sheet of foil covering the top opening of the caldero and cover with lid. Cook the Puerto Rican rice for 30 minutes over medium heat without opening the lid at all. Fluff rice and add salt for personal taste.