How to Make It
Put the black beans in a large bowl and add enough water to cover. Let soak overnight. Drain before using.
In a large saucepan, combine the beans with the onion, bay leaf and 12 cups of water. Bring to a boil, then reduce the heat to low and simmer, stirring occasionally, until tender, about 1 hour. Drain the beans, then transfer them to a bowl and season with salt. Keep covered until ready to use.
In a large saucepan, rinse the rice in several changes of water, then drain. Return the rice to the pan, add 3 1/2 cups of water and bring to a boil. Add 2 teaspoons of salt, stir in the diced squash and return to a rolling boil. Cover, reduce the heat to low and cook without uncovering for 14 minutes. Uncover and stir the rice to fluff it. Cover again and let the rice stand off the heat for 5 minutes. Stir in the black beans and serve at once.