Soak the beans overnight.
Roast peppers on the stovetop on medium-high heat. A gas stove works the best but it will work fine on an electric stove.
Char the peppers on all sides turning with a pair of tongs. When good and charred, steam them for 10 minutes in a covered dish or a paper bag rolled shut to hold in the steam.
Take a paper towel and rub off the char. It’s ok to leave a little of the char. Slice in half and remove the seeds and stems then dice them.