How to turn shellfish shells into stock – recipe

Shellfish are an expensive delicacy, so are well worth using in their entirety. Fortunately, even once it’s been picked of all accessible meat, the rest of the crustacean is useful from shell to claw. Even the most experienced shellfish eater will leave some meaty morsels in the nooks and crannies of the carapace, while the heads are full of flavourful juices that can be sucked out or combined with a holy trinity of stock vegetables and aromatics to make an exquisite stock for bisques, broths, risottos or paellas. Collect picked shells in the freezer until you have enough to make today’s small-batch recipe, or bulk it out with other fishy remnants if necessary.

Shellfish stock
A rich, nourishing stock is a great way to ensure you get the most bang for your buck when you treat yourself to a shellfish dinner. Homemade shellfish stock will up your home cooking game, helping you make the most flavourful, restaurant-quality paellas, risottos, gumbos and curries at home.

If your oven is already in use, instead of sauteing the shellfish shells, roast them at a high heat – 240C (220C fan)/475F/gas 9 for about 10 minutes, which has the added bonus of ensuring a a more even caramelisation (however, avoid roasting shellfish with other foods that might absorb its odour).

Whenever we cook shellfish at home, I semi-automatically get a pot of stock on the go after the meal, and if you go down that route, add any appropriate leftover vegetables from the meal to the stock pot, too. For more ideas about cooking with shellfish, and specifically crab, check out this article I wrote for Guardian Cook back in 2016.

2 tbsp oil
500g shellfish shells and offcuts
50ml white wine
1 small onion
1 green leek top
1 stick celery
1 small carrot
½ small fennel bulb (or ½ tsp fennel seeds)
3 garlic cloves, peeled
3 bay leaves
3 sprigs fresh thyme or oregano (or 1 tsp dried)
1 tbsp tomato puree

Put one tablespoon of the oil in a large, heavy-based pan over a medium heat. Add the shellfish shells, heads, legs and any offcuts and cook slowly, stirring occasionally, for 10 minutes, or until the shells become caramelised and turn red. Add the white wine and bring to a boil, stirring.

Meanwhile, put the remaining tablespoon of oil in a second pan over a medium heat, then add the onion, leek top, celery stick, carrot and fennel, and cook, stirring, for 10 minutes, until caramelised.

Tip the veg into the shellfish pan, then add the garlic, bay leaves, thyme or oregano and tomato puree, cover with water and bring to a boil. Turn down the heat to a simmer and leave to bubble gently for two hours, skimming off any scum as it rises to the surface.

Once cooked, strain the stock through a fine sieve or muslin, then leave to cool, box up and refrigerate for up to five days or freeze.