This is neither an especially easy nor an especially difficult dish to pull off. Everything on the plate is cooked simply and separately, and it all pulls together quickly at the end. Think of it almost like a composed salad. The toughest part of making this recipe is getting some of the ingredients. Sturgeon can be tough to find, but swordfish is in most fish markets in the country. Buy North American-caught swordfish, which is sustainable. You can use any firm, white fish. California white seabass, tilefish, shark, paddlefish or even redfish would work.
2poundsjerusalem artichokes,trimmed of any dirty or dark spots
1poundsturgeon or other firm fish,cut into cubes
3white radishes,sliced paper thin on a mandoline
Horseradish root for grating
For the asparagus, bring a small pot of water to a boil. Salt it so it tastes like the ocean. Boil the white asparagus until al dente, about 5 minutes. Drain and toss with olive oil. Set aside.
For the mushrooms, pour the rice vinegar and 1/2 cup water into the pot you cooked the asparagus in. Trim the root ends off the enoki mushrooms and boil them in the rice vinegar for 3 minutes. Cover the pot and turn off the heat.
For the jerusalem artichoke puree, trim the 'chokes of any dark spots or dirt. You don't need to peel them if you don't want to. Add them to a pot of water and bring it to a boil. Salt the water well and simmer gently until the jerusalem artichokes are tender, about 30-40 minutes. Move the cooked sunchokes to a blender and add the sour cream. Puree. You may need to scrape the sides of the blender down to get everything into a smooth puree. Push this puree through a fine-meshed sieve and add salt if needed. Put into a pot set over very low heat and cover.
For the fish, cut it into large cubes and salt well. Set a large saute pan over high heat for 1 minute. Add 1 tablespoon olive oil. While this is heating up, pat the fish dry with a paper towel. Set the largest, flattest side of the fish cube into the hot oil and sear, untouched, for 3 minutes. Turn the heat to medium-low and "kiss" the remaining sides of each fish cube for 30 seconds. You don't want the other sides to brown.
To serve, lay down some jerusalem artichoke puree and make a well in the center with a spoon. Place the sturgeon down, browned side up. Arrange the mushrooms and asparagus in between the fish, then place some thinly sliced radishes here and there. Don't grate the horseradish over the plates until they are all done; horseradish loses its flavor fast. Serve immediately.
Enoki mushrooms are sold in Asian markets, and if you can't find them, use white button mushrooms. The look will be different, but you'll get the same flavor. White asparagus is available in decent supermarkets in spring; there is no substitute if you want an all-white plate. Jerusalem artichokes are available in some markets, but you can easily substitute potatoes.
The White Sturgeon https://honest-food.net/white-sturgeon-and-fine-dining/ March 8, 2012