Rinse the beans under cold water, sorting out any rocks or particles. Place the beans in a stockpot with the ham hock and cover with water by 2 inches. Bring to a boil, and then reduce to a simmer. Cover the pot and simmer for 2 hours, checking occasionally to make sure the water level is fine. Add more water as needed.
Throw in the garlic, red bell peppers and onions. Cover and continue cooking for another hour or two, remembering to check the water level.
Add the chili powder, black pepper, and salt (or more to taste). Then cover and cook until the beans are lovely and tender, another 20 to 30 minutes. The liquid should be very thick and stew-like, not thin like a soup.
Serve with cornbread as a meal, or spoon on top of nachos, tacos, etc.