I recommend you slow cook this, it is well known that slow cooked beans are so much better!
If your slow cooker is small, half the recipe.
If you can’t find Anaheim peppers, you can use serrano peppers, but the flavor will change. Some people also prepare it with chile guajillo (chile Colorado) which is essentially dried Anaheim pepper.
The original recipe contains beef, but you can substitute with jackfruit, mushrooms or your favorite meat substitute. I prefer to simply omit the beef and I quite enjoy it. Enjoy!!