Ham hocks are one of the tastiest, cheapest things you can cook and keep in your fridge. Good butchers and some supermarkets have ham hocks, both smoked and unsmoked.
1 ham hock, soaked overnight in cold water
10 black peppercorns
1 bay leaf
1 large onion, halved
5-6 sticks of celery, peeled if stringy and cut into rough 1cm dice
A handful of celery leaves, chopped
Drain the ham hock and then give it a good rinse under cold water. Place it in a large saucepan with the peppercorns, bay leaf and onion, cover well with water, bring to the boil and simmer very gently for about 2-2½ hours with the lid on or until tender and just falling away from the bone. (You can cook the hocks in approximately half the time in a pressure cooker if you have one.)
Strain the stock through a fine-meshed sieve and place the hock on a plate to cool. Melt the butter in a heavy-based saucepan and gently cook the celery for 2-3 minutes until it begins to soften.
Stir in the flour, then gradually add 1.2 litres of the hot stock, stirring continuously to avoid lumps forming. Simmer gently for 20 minutes. Meanwhile, remove half of the ham hock from the bone and cut into rough, 1cm chunks (save the rest for another meal and the skin is great crisped up in a salad).
Add to the broth with the celery leaves; season to taste if necessary and serve.