To prepare a Spanish seafood stew recipe, first you'll need to gather your ingredients. First, you will need: 1 pound (240 g) of shrimp, 2 lbs. of halibut, 1/2 cup (120 ml) chopped sardines, 1 chopped red onion, 3 tablespoons of olive oil, salt, and pepper to taste. You will also need 2 cups of water. Add the shrimp to the boiling water and cook them for 5 minutes. Then, add the rest of the ingredients and stir to combine. Cover the pot and simmer the mixture for 1 hour. Remove the pan from the heat and serve the stew immediately.