How long do black beans take to cook?
About 2 hours at a simmer, until soft enough to squeeze between your fingers. Check periodically and add water as needed to keep them submerged.
Can I use canned black beans instead of dried?
Yes. Use 4-5 cans of drained black beans and skip the 2-hour cooking step. Start at step 5 with the caramelized onion base, then combine and simmer for 5-10 minutes.
Why only partially blend the beans?
Blending 10-20% of the top layer (where onions and chiles float) thickens the mixture and creates a sauce without losing the beans' texture. Over-blending results in a smooth purée instead of beans in a thick sauce.
How do I store leftovers?
Refrigerate in an airtight container for up to 4 days. Reheat gently on the stovetop with a splash of water or broth to restore creaminess.
What oil works best for caramelizing the onions?
Use a neutral oil like rapeseed or vegetable oil that won't brown or burn during slow cooking over medium-low heat.