Why-Is-It-So-Good Gravy

Preheat oven to 450°F. Toss wings in a large cast-iron skillet with 2 Tbsp. oil until coated. Roast, tossing halfway through, until golden brown and starting to crisp, 25–35 minutes.

Remove wings from oven and add garlic, shallots, ginger, mushrooms, peppercorns, and remaining 2 Tbsp. oil to pan; toss to coat. Return to oven and roast, tossing halfway through, until wings are deeply browned and crisp and vegetables are browned, 30–40 minutes more.

Meanwhile, mash together flour and butter in a small bowl with your fingers or a fork until homogenous. Set beurre manié aside.

Remove skillet from oven and set on stovetop over medium-high heat. Add sherry and cook, stirring and scraping up any browned bits with a wooden spoon, until sherry is almost completely reduced, about 2 minutes.

Scrape wings and aromatics into a medium pot and add parsley and stock. Bring to a low simmer over medium-high heat. Reduce heat and simmer gently, skimming fat from surface occasionally and turning wings so both sides get a chance to be submerged, until liquid is flavorful, mahogany in color, and reduced by about one-third, 30–40 minutes.

Fish out wings; discard. Pour mixture through a fine-mesh sieve into a large measuring glass; discard solids. Rinse out pot and pour turkey mixture back in. Bring to a simmer over medium. Whisking constantly, add reserved beurre manié and whisk until completely incorporated. Simmer, whisking often and skimming any foam from surface, until gravy is thick enough to coat a spoon, 6–8 minutes. Remove from heat and whisk in vinegar and MSG. Taste gravy and season with salt and pepper if desired. DO AHEAD: Gravy (without vinegar and MSG) can be made 5 days ahead. Let cool, then cover and chill. Reheat over medium until simmering, then add vinegar and MSG.