Here’s a simple seafood stock recipe that makes use of those crab and shrimp shells we always encourage you to save. With just a bit of aromatics and gentle simmering, shrimp and crab shells impart sweetness and depth of flavor to soup stock. For an enriched stock, substitute half of the water with bottled clam juice.
1 tablespoon vegetable oil
4 to 5 cups crab and shrimp shells, from about 2 crab clusters and 1 pound shrimp
Green tops from 1 leek or 1 small yellow onion, coarsely chopped
1 tablespoon tomato paste
1 small dried bay leaf, preferably Turkish
1 teaspoon whole peppercorns
6 cups water (or 3 cups each water and clam juice)
6 fresh thyme sprigs
Cook the Aromatics
Heat the oil in a medium pot over medium heat. Add the crab and shrimp shells and cook, stirring and pressing until fragrant, about 5 minutes. Stir in the leek tops, tomato paste, bay leaf, and peppercorns. Cook, stirring, for 2 to 3 minutes.
Simmer the Stock
Add the water (or water and clam juice) and thyme and bring to a boil. Reduce heat to low and simmer until the liquid is flavorful and slightly reduced, about 30 minutes.
Strain the Stock
Strain the stock through a fine-mesh sieve, pressing hard on the solids. Use right away or cool to room temperature and freeze in an airtight container for up to 1 month.
Change It Up
For a taste of the south of France, sauté the stalks and fronds of a fennel bulb with the aromatics and add a pinch of saffron to the simmering liquid.