Pour uncooked rice into rice cooker. Sprinkle Sazon Goya and dried cilantro on top of rice. Add water according the manufacturer’s directions. Turn the cooker on and let it go to work.
While the rice is cooking, saute onions and garlic in 6 quart pot over medium heat, until translucent. Add the tomatoes, salt, and black pepper and cook, stirring occasionally, until the tomatoes release their juices. Reduce heat and cook on low for about 10 more minutes.
Add the black beans (undrained), garbanzo beans (drained), and the corn. Stir well and increase heat to medium. Once it starts to boil, reduce heat and cook covered for about 20 minutes until the beans are tender.
Stir in the chopped cilantro and cover again. Allow to cook over low heat for just five minutes.
Gradually add rice to the beans and tomato mixture. Scoop in a large spoonful and stir. Continue adding until all the rice is incorporated. Serve immediately, garnished with cilantro leaves.