Heat cooking fat in a saucepan over medium heat.
Cooking fat
Add the onion, garlic, celery, fennel, and chili flakes. Cook for 4 to 5 minutes.
1 red onion, 2 garlic cloves, 2 celery stalks, 1 small fennel bulb, ½ tsp. chili flakes
Deglaze the pan with the fish stock, scraping the bottom of the pan.
2 cups fish or chicken stock
Pour in the tomato paste and grated butternut squash; bring to a boil, then lower the heat.
2 cups tomato sauce, 1 cup butternut squash
Add in the halibut, salmon, shrimp, and sea scallops.
½ lb. halibut fillet, ½ lb. salmon fillet, 20 raw shrimps, ½ lb. sea scallops
Simmer for 20 to 25 minutes.
Add in the lemon juice and season to taste. Serve topped with parsley and lime wedges.
Juice from ½ lemon, ¼ cup fresh flat-leaf parsley, Sea salt and freshly ground black pepper