"These beans are a riff on a James Beard (not Bostonian) recipe, but it is amazing and holds a week or 10 days in fridge. And it It makes a great soup base -- just add extra veg and stock, and give it a quick purée."
Soak beans in a large bowl covered with 2 to 3 inches of water overnight OR soak them in boiling water for 1 hour. Drain beans and rinse.
Heat oven to 250°F or a slow cooker to medium-high/high.