Cover beans with water and soak overnight in a dutch oven. Drain beans. Add water to cover by 1". Bring to a boil, cover and simmer 20 to 30 min. until tender. Drain and save the liquid.
Preheat oven to 350. Place beans in dutch oven or roaster with 5 c. bean liquid, sugar, mustard, pepper & molasses. Add meat and onions and bake for 3 to 4 hours. Stirring often...if they get dry add more bean liquid.