Drain and discard soaking liquid. In a 3-quart saucepan, sauté bacon until it begins to crisp, about 5 minutes.
Add onions, bell pepper, cumin, and 1/2 tsp. salt. Continue to cook about 5 minutes longer, until vegetables are softened. Stir in garlic and oregano and cook until fragrant, about 30 seconds.
Add water, beans, bay leaves, and red pepper flakes. Bring to a boil. Pour into a large crock pot and cook on HIGH for 3 to 4 hours or LOW 7 to 8 hours (see notes).
Remove and discard bay leaves. Add cilantro and lime juice and season to taste with salt and pepper.
Notes
Slow cooker times may vary. The first time you make the beans, please check them after 3 or 4 hours on HIGH and continue cooking longer if necessary. If the beans have any crunch to them at all, please cook them longer.You can use either Italian or Mexican oregano. They have different flavors (Mexican oregano tastes more like marjoram) but both taste great in this recipe. Feel free to use whatever you have.Pre-soaking the beans:Soaking the beans before cooking is not required. However, you can cut about 30 minutes off the cooking time if you pre-soak the beans. WARNING: If you substitute dried kidney beans, you MUST pre-soak them and boil them for at least 10 minutes.Overnight-Soaking Method for beans:
Pick through and rinse 1 pound beans.
Cover the beans with 5 cups over water and soak overnight.
Drain and discard soaking liquid.
Quick-Soaking Method for beans:
Pick through and rinse 1 pound beans.
To a large saucepan, add beans and enough liquid to cover them by 1 inch.
Bring beans to boil and cook for 2 minutes.
Remove saucepan from heat, cover, and let beans sit for 1 hour.
Drain and discard soaking liquid.
To substitute canned beans:Use 3 or 4 cans of black beans. Rinse and drain before adding to the pot and cook until heated through, about 15 to 20 minutes.Adapted from America's Test Kitchen Healthy Cookbook.