For the loup de mer: Put the thyme and lemon and orange zest together in a bowl and, while stirring, slowly drizzle in enough olive oil a little at a time to form a paste; it should not be runny, just moist.
Salt the fish and cover it with the citrus paste; let sit in the refrigerator until the other components have been completed.
For the beer blanc: Fill a medium pot about 3/4 full with water and place over low heat. The water should be warm to the touch but not hot.
Sweat the shallots, fennel and olive oil in a saucepan over medium heat until the shallots are transparent, about 3 minutes. Pour in just enough canola oil to coat them, and then add the salt. This will ensure the vegetables don't brown as the salt pulls moisture out of them and creates a steaming effect. After about 1 minute, add the beer and vinegar and stir to combine.
Simmer the mixture until reduced by half, about 5 minutes. Add a splash of water or fish stock and reduce the heat to low. Whisk in 12 tablespoons of the butter, one cube at a time, waiting until it is completely incorporated before adding more.
Strain the mixture through a fine mesh sieve. Discard the solids and transfer the liquid to a powerful blender (or use an immersion blender set to high) and process while adding the remaining 4 tablespoons butter a little at a time. The emulsion will not be stable for long, so transfer the mixture to a heat-proof bowl and place it over the pot of warm water on the stove to keep it warm. The sauce does not hold in the refrigerator, so discard after use.
For the potato and fennel hash: Put the potatoes in a pot and cover with cold salted water. Bring to a boil and remove from the heat. Let the potatoes sit in the water until soft, about 10 minutes. Strain off the water and spread out in a single layer on a flat surface to cool.
Sweat the shallots, garlic, carrot, celery and fennel with the oil in a saute pan over medium heat until soft but not colored. Add the cooled potatoes, the chicken broth, butter and pinch of salt. Reduce over medium heat until there is only enough liquid to glaze the vegetables. Remove from the heat, add the lemon juice and taste for salt, adding more if necessary.
To serve: When the beer blanc sauce and potato and fennel hash are completed and holding, heat a grill or grill pan to high and and grill the fish skin-side down, until 70 percent cooked, 2 to 3 minutes. Carefully turn over the fish and cook on the flesh side for only about a minute or so.
Place some beer blanc on 4 plates. Place some potato and fennel hash in the middle of each plate. Top with the fish skin-side up. Garnish with the fennel fronds if desired.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Dustin Haney, Executive Chef and Partner, Scratch Restaurant, Winter Park, Florida