PUT in a pressure cooker all the beans and add water to fill ¾ of the pot. Let cook for 50 minutes after the pressure cooker begins to whistle. RINSE rice for several times until running water is transparent. Drain it well. HEAT 2 tablespoons of oil in a pan over medium heat. Fry rice for several minutes until it looks transparent, don´t let turn too brown. BLEND onion and garlic with a little of beans brith, pour over the fried rice and let it boil. INCORPORATE the rest of bean broth, whole beans and epazote; season with salt. Let it boil again, reduce heat, cover and cook until rice gets soft and soup has consumed, 20 minutes approximately. Turn off heat and stir carefully with a fork. HEAT the rest of the oil in a big frying pan over medium heat. Peel plantains and chop then in diagonal slices. FRY slices in hot oil until they turn brown on both sides. Dry them on paper towels. SERVE, moros and cristianos along with plantain slices.