My husband's aunt makes beans this way and they are delicious!!
1 cup dried black beans (or you can use pinto)
1 onion, chopped
several cloves garlic, chopped
1 bunch beet greens or fresh spinach, washed and chopped
Soak the beans several hours or overnight. When ready to cook, bring to a boil and cook them with the onions and garlic until beans are tender and liquid is reduced. The beans should not be dry, but the liquid should be reduced and kind of thick. When the beans are tender, add the greens and cook until done. Season to taste with salt.
For refried black beans: Omit the greens. Heat oil or shortening in a pan until hot; saute some chopped onion and several cloves of diced garlic until soft; add beans and enough liquid so they aren't too dry. Mash with a potato masher or fork. When they are well mashed, you can add grated cheese, cover and reduce heat to low until cheese is melted. This works for pinto beans as well, but black beans are especially delicious refried.