Serves 4
Heat oven to 200°.
Dry the fish with paper towels, season lightly with salt, pepper and Old Bay if using. Dredge lightly with Wondra flour.
Add enough oil to coat the bottom of the pan and brown on both sides. Remove to an oven proof plate, place in the oven while you make the sauce.
Sauce:
Cut the butter into medium (1/2-inch) cubes and return the butter cubes to the refrigerator to keep them cold, which is very important.
Heat the wine, vinegar, and shallots in a saucepan until the liquid boils, then lower the heat a bit and continue simmering until the liquid has reduced down to about 2 tablespoons.
Once the wine-vinegar mixture has reduced to 2 tablespoons, reduce the heat to low, take the cubes of butter out of the fridge and start adding the cubes, one or two at a time, to the reduction, while you whisk rapidly with a whisk.
As the butter melts and incorporates, add more butter and keep whisking. Continue until you only have 2 to 3 cubes remaining. Remove from heat while whisking in the last few cubes and whisk for a moment or two more. The finished sauce should be thick and smooth.
Season to taste with sea salt, add herbs and serve over fish with lemon wedges, if using.