In a large pot over medium heat, add 1 tablespoon of the oil and add half of the garlic, half of the onions
, half of the peppers and half of the cilantro stems. Cook until tender, 5 to 6 minutes. Add the rice and saute for 2 minutes. Add 3 cups water and bring to a boil. Cover and reduce the heat to simmer until rice is tender, 20 to 35 minutes. Turn the heat to low and continue to cook the rice until the bottom is golden brown and crispy, 1 hour.
While the rice is cooking, heat a large pot over medium heat. Add the remaining 1 tablespoon oil and the remaining onions, peppers, garlic and cilantro stems. Cook until tender, 5 to 6 minutes. Add the black beans and cover with 1 inch of water. Cover the pan and reduce the heat to very low. Simmer until the beans are soft, 3 hours. At about the 2 hour mark, add the sausage.
Serve the rice, beans and sausage with warm corn tortillas and garnish with the chopped cilantro leaves.