Cut small leeks into 1 cm slices and soak in cold water for 20 minutes, to remove any soil from between the layers. Boil new potatoes cut into bite-sized chunks
for about 15 minutes, until just cooked, drain and set aside. Boil a few frozen broad beans for 5 minutes, drain and set these aside also. Fry bacon lardons
in a little oil until golden and crispy, remove and set aside. Add a chopped onion and the drained leeks to the pan along with a knob of butter if there isn't enough fat,
cover and cook gently for 5 minutes or so, until softened. Sprinkle with a Tbs plain flour, mixing well to mop up all the fat, then add 300 ml of stock – fish or chicken.
Stir well and simmer until slightly thickened, then add the potatoes, beans and bacon, along with 100 ml cream and 50-70 g grated strong cheddar. Cook gently until
the cheese melts and the sauce thickens, season with freshly-ground black pepper, then add 300 g skinless cod cut into 2 cm chunks and a few halved cherry tomatoes,
simmer slowly for another 2-3 minutes, until the fish is just cooked. Serve in bowls, garnished with chopped parsley.