(from the kitchen of Elenita Darling)
Country of origin: Mexico
Elenita Darling is my cousin that lives in Mexico City.
4 Cups pinto beans
1 or 2 Tablespoons Baking soda
1 onion
1 Tablespoon salt
1 lb. bacon
1 lb. chorizo sausage
1 8oz. can tomato puree
1 bunch cilantro

Wash beans thoroughly by placing beans in a colander in the sink and running water over it while washing the beans by hand, rinsing through several times, making sure they are completely clean. Soak beans in tall stockpot overnight with baking soda.(It is said that the soda removes some of the gas.) Make sure water covers beans allowing them to still be covered with water after doubling in size during soaking process. In the morning, drain into colander and rinse thoroughly. Pour beans into pot. Add whole onion, salt, and cover with water. Bring to a boil and simmer until soft, 1 or 2 hours. Remove whole onion. While beans are cooking, fry bacon in pan. Drain grease and set bacon aside. Fry chorizo in pan and cut in pieces. Drain grease. Mix in bacon and cook in pan until it all combines. Drain grease. Add tomato puree. When tomato mixture changes color add diced cilantro. Up to this point, beans should still be soaking in its broth. Add the tomato mixture to the beans. Let boil and simmer. Stir well. Serve with tortillas.