Sort and soak beans overnight; drain and discard soak water
In a 4-quart pot, saute onion in butter or marg until tender but not browned
Add soaked beans, 4 cups water, bouillon cube, ham (cut into 4-6 chunks), bay leaves, thyme, oregano, salt & red pepper
Bring to boil; reduce heat
Cover and simmer until beans are tender, 1 to 1-1/2 hour
Remove 1 cup beans from stew, mash in a bowl with potato masher or fork
Add mashed beans to stew; stir to thicken
Remove ham and dice
Remove bay leaves and red pepper, if used, and discard
Add diced meat, green pepper and rum (if desired) to beans
Cover and simmer 15 minutes
Serve beans over rice and top with sour cream if desired