- Coarse sea salt or kosher salt
- 1 cup peeled, sliced shallots
- 1 cup dry white wine
- ¼ cup white wine vinegar
- 1 tablespoon gin
- 12 juniper berries: 4 finely crushed; 8 left whole
- 1 teaspoon crushed black pepper
- 1 small head savoy cabbage (about 2 pounds), quartered, cored, and cut into 1-inch wedges
- 1½ pounds Yukon Gold potatoes, peeled and cut into 1/8-inch-thick slices
- ¾ pound unsalted butter (3 sticks), cut into tablespoon-size pieces and chilled
- 1(3½-pound) monkfish tail, on the bone (have your fish dealer remove the skin and membrane)
- Freshly ground black pepper
- ¼ pound smoked country bacon, cut into ½-inch-thick strips
- 1 large onion, peeled and thinly sliced
- 2 bay leaves
- 1 small bunch round red radishes, thinly sliced, for garnish (optional)
- Put a rack in the lower third of the oven and preheat the oven to 300°F. Bring a large pot of salted water to a boil.
- To make the beurre blanc: In a medium saucepan, bring the shallots, wine, vinegar, gin, crushed juniper berries, and black pepper to a boil and simmer until reduced to ¼ cup, about 20 minutes.
- Meanwhile, add the cabbage and potatoes to the pot of boiling water and blanch until tender, 5 to 7 minutes. Transfer to a colander to drain.
- When the beurre blanc reduction has finished, reduce the heat to low and add the butter, 1 piece at a time, whisking until just melted before adding more. The sauce should have the consistency of a hollandaise. Strain the beurre blanc through a fine-mesh sieve, pressing on the solids to extract as much liquid and flavor as possible. Season to taste with salt and cover to keep warm (the sauce will break if it gets too hot or too cold).
- Wash the monkfish, pat it dry, and season it with salt and pepper. In a medium cast-iron pot or Dutch oven, cook the bacon over medium heat until it is translucent (adjust the heat so it does not brown), 5 to 7 minutes. Add the onion, bay leaves, and whole juniper berries and cook, stirring, until the onion is translucent, about 10 minutes. Add the cabbage and potatoes, pour the beurre blanc over the vegetables, and arrange the monkfish on top (cut the monkfish tail crosswise in half if it is too long for the pot). Cover the pot and transfer it to the oven.
- Braise until the fish is cooked through, 25 to 35 minutes. Garnish with the radish slices, if using, and serve.