Shellfish Stock

500g shellfish shells, such as lobster or prawn shells1 small onion, peeled and halved

1 carrot, rough chopped

good dash of tomato purée

400ml white wine 

1 bay leaf

olive oil

1 lemon, halved

1 handful parsley stalk

4 celery sticks, chopped

8 peppercorns

pinch of salt

3 litres water

Place the olive oil in a large pan or stock pot and lightly sweat the shellfish shells , then add the other dry ingredients and use a rolling pin to crush the shells lightly, then add the wine and let reduce away then add the tomato puree and cover with the water. Bring to the boil and then reduce to a simmer for 30 to 60 minutes, skimming off any foam and scum that rises to the surface, depending how intense you want your stock. Strain through a muslin lined sieve and use straight away or cool and store.