Heat the olive oil in a large saucepan over medium heat. Add the onions, celery and garlic and cook until softened, 8 to 10 minutes.
Add the wine and simmer until slightly reduced, 3 to 5 minutes. Add the tomatoes, parsley, crushed red pepper, thyme, salt and pepper and cook over medium heat for 12 minutes. Remove from the heat and add the cream.
Bring 2 quarts water to a boil in a separate pot. Add the cod, mahi-mahi, shrimp and scallops and cook until cooked through and no longer translucent, 5 to 7 minutes. Drain and add to the stew.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.