In a medium saucepan, combine beans, bicarbonate of soda and cover with water. Bring to the boil, remove from heat and allow to stand for at least two hours. Return saucepan to the heat, bring to the boil, drain.
Heat oil in a large enamelled cast-iron casserole and sauté onion and garlic.
Add the remaining ingredients, including the beans and bring to the boil.
Place the ham hock on top of the beans, cover and place casserole in preheated oven for 4-5 hours.
Remove hock from casserole, discard skin and bone, shred meat. Remove bay leaves before returning shredded meat to the beans. Serve on toast.