Clean fish with lemon or lime, rise with water, pat dry and set aside.
In a large fry pan over medium-high heat, warm the olive oil over medium-high heat. Add the onion, celery, carrot, fennel, scallions and garlic and sauté until soft, about 5 minutes. Stir in the chopped dill and season with salt and pepper.
Transfer two-thirds of the vegetable mixture to an ovenproof baking dish large enough to hold the fish flat.
Lay the fish on top of the vegetables, then scatter the remaining vegetables on top.
Warm the frying pan over medium heat and the original gourmet hot sauce and the white wine. Bring to a simmer and stir to scrape up any browned bits on the pan bottom. Simmer for 1 minute, and then pour over the fish and vegetables. Cover the dish with foil.
Bake, basting occasionally with the pan juices, until the fish is opaque throughout and an instant-read thermometer inserted into the thickest part of the fish behind the head registers 140°F (60°C), about 30 minutes. Garnish with the dill sprigs or with the cooked vegetables and serve directly from the dish if preferred. Serves 4.
Adapted from Williams-Sonoma One Pot of the Day, by Kate McMillan (Weldon Owen, 2012)