In a large Caldero or rice pot, brown the longaniza (no oil needed) on high heat. Once the sausage has browned, remove from the pot and transfer to a plate.
Discard some of the oil from the pot and leave about a tablespoon. Add the diced onion, sofrito, (or see note*) chicken bouillon, and tomato paste. Stir until the chicken bouillon has mostly dissolved and the tomato paste is well incorporated. Add the drained rice to the mixture, stir.
Pour the water into the rice, stir again, and bring it to a boil. When most of the water has evaporated, lower the heat and cover with an airtight lid. Let the rice simmer for about 12 to 15 minutes.
Uncover the rice, add the cooked longaniza and olives, turn once, and cover again for another 5 minutes.
Taste the rice; it should be firm but tender to the bite. Serve with stewed beans and salad.