1cupfinely minced parsley, fennel fronds, dill, chervil, or cilantro
Lemon juice to taste
Salt and pepper the fish and set aside while you chop the vegetables and herbs.
Set a cooling rack over a baking sheet and put that in the oven. Set the oven to 200°F.
Heat 1 tablespoon of the olive oil in a small pan and gently cook the onion until it is golden and translucent. Don't brown it. Turn off the heat and let everything sit for now.
Heat the rest of the olive oil in a large sauté pan over medium-high heat. While it is heating up, dust the fish with flour. Press the flour in, then shake off the excess. Fry the fish in the olive oil until nicely browned on both sides, about four minutes per side. Move the fish to the rack in the oven as it browns.
When the fish is ready, move the onion and as much of the oil as you can scrape out of the little pan into the pan you cooked the fish in. Let this heat up, adding the garlic now. Let all this cook a minute or two.
Pour in the wine, bring it to a boil and let it roll a minute or two, then pour in the fish stock. Bring this to a boil and let it cook down for a couple minutes. Taste it for salt and add some if needed. Add all the herbs and cayenne and stir to combine. Let this cook 1 minute, then turn off the heat. Add black pepper and lemon juice to taste.
Pour some sauce over the fish on everyone's plate and serve with crusty bread, potatoes or rice.