Duck Breast, Buttermilk-poached Winter Vegetables, and Cornbread Purée
For the Aged Duck:
Make a 10 percent salt water solution and chill. Submerge duck in brine and refrigerate for 4 to 6 hours. Drain duck and hang by its neck in refrigerator, close to the fan, for 10 days.
For the Smoked Buttermilk Curd:
In a stainless steel pot, combine milk and buttermilk. Over low heat, bring mixture to 145°F. Add rennet and gently stir. When mixture reaches 165°F, add lime juice. Remove from heat and rest 15 minutes. Drain curds, setting aside whey for Buttermilk Sauce and Root Vegetables. Prepare and heat a smoker with pecan wood. Cold smoke remaining curds for 30 minutes. Transfer smoked curds to mixer fitted with whisk. Add remaining ingredients and whip until combined. Cover and chill in refrigerator.
Heat oven to 400°F. Heat 10-inch cast-iron pan over medium flame, coating it in duck fat. In a mixing bowl, whisk together cornmeal, baking soda, and salt. In a separate bowl, whisk together egg and 1½ cups buttermilk. Whisk buttermilk mixture into cornmeal mixture. Add half the melted butter and whisk to combine. Pour batter into pan and transfer pan to oven. Bake 20 minutes and remove from oven. Let cool in pan for 10 minutes. Crumble half the cornbread into a small saucepot with the remaining butter. Toast until golden brown. Add remaining buttermilk and cook to porridge-like consistency. Stir in Aleppo pepper, sorghum, and ¼ cup Smoked Cheese Curds. Transfer mixture to blender and purée. Adjust consistency with heavy cream and butter. Season with salt. Pass through chinois. Cover and reserve warm.
For the Buttermilk Sauce:
In a small stainless steel saucepot, combine whey and buttermilk. Bring mixture to a simmer. Reduce by half. Gradually whisk in butter until all cubes are incorporated. Remove mixture from heat and season with lemon juice and salt. With an immersion blender, sheer in xanthan gum. Cover and reserve warm.
For the Root Vegetables:
Place each vegetable in its own small stainless-steel pot with 1 cup whey and 1 bay leaf each. Simmer vegetables until just tender. Drain vegetables and cool on sheet tray.
For the Duck Breast:
Break down Aged Duck, removing head and feet first, setting them aside for another use. Remove neck, wings, and thighs and set aside with feet. Position duck with neck opening down and split duck down middle, leaving the breastplate attached to breast meat. Set aside remaining carcass with feet. Rest a chinois in a bain marie. Season duck breast with kosher salt and pepper. Transfer to a cold, 12-inch pan, fat-side down. Over medium-low heat, render fat 3 to 5 minutes. Tilt pan and baste breastplate with fat 15 to 20 times on the fatter end by the wishbone. Flip duck and baste 15 to 20 times. Strain fat through chinois set over the bain marie. Flip duck and repeat rendering and basting process 2 to 3 times, until most of the fat renders and skin is crisp. Add 1 tablespoon strained duck fat to a pan with thyme, garlic, and butter. Add duck and cook to medium rare, fervently basting duck on both sides. Remove duck from pan and rest. With a pairing knife, gently remove wishbone. Skin-side down, carefully carve the duck breast from the breastplate by cutting thin slices against the grain. Season each slice with sea salt.
To Assemble and Serve:
Reheat Root Vegetables in Buttermilk Sauce. Plate a swipe Cornbread Purée. Lay Duck Breast slices on top and scatter vegetables around the plate. Garnish with micro greens.