Preheat the oven to 350 degrees F (175 degrees C).

Pat chicken breasts dry with a paper towel. Combine sazon seasoning, chili powder, and pepper in a small bowl. Season each chicken breast with sazon spice mix, making sure to get some seasoning under the skin as well as on the outside.

Heat a 10-inch skillet over medium-high heat. Add olive oil to the hot pan, and place chicken breasts skin-side down in the skillet. Brown chicken, about 4 minutes. When skin is brown, move chicken to a plate. Add sofrito, tomato paste, and cumin to the same skillet and cook, stirring, for 1 to 2 minutes. Add chicken stock and bring to a boil. Stir in riced cauliflower and nestle chicken down into the mixture. Cover.

Bake in the preheated oven for 25 minutes. Stir in peas and salt, and bake, uncovered, until the chicken is no longer pink at the bone, the juices run clear, and most of the liquid has cooked down, 15 to 20 minutes more. An instant-read thermometer inserted near the bone should read 165 degrees F (74 degrees C). Serve hot.