How to Make It
Place beans, onion, garlic, bay leaf, 6 cups water, and 1 teaspoon salt in a 4- to 6-quart slow cooker. Cover and cook until beans are tender but not falling apart, 6 to 7 hours on low or 3 to 4 hours on high. Discard onion, garlic, and bay leaf. Stir in remaining 1/2 teaspoon salt.
To freeze: Let beans cool to room temperature. Transfer to reusable freezer-safe containers and cover beans completely with their cooking liquid. Cover and freeze for up to 6 months. Thaw in the microwave or overnight in the refrigerator. Reheat in a pot on the stovetop over low.
Serving suggestion (shown): Top beans with crumbled cotija cheese and cilantro. Serve with lime wedges.