2
Heat remaining 1 Tbsp. oil in stockpot over medium. Add onion, carrots, celery, garlic, and mushrooms and cook, stirring occasionally, until softened and lightly browned, 10-15 minutes. Add ham hock, parsley, bay leaves, wine, peppercorns, and a pinch of salt. Bring to a boil and cook until wine is evaporated, about 5 minutes. Add wings and use a wooden spoon to scrape any crispy bits off baking sheet. (Add a little water to help loosen if needed.) Add another pinch of salt and 2 gallons water; bring to a boil. Reduce heat to low and simmer, uncovered, until meat is falling apart and liquid is reduced by half, 3 1/2-4 1/2 hours (go the full distance for a rich and gelatinous stock).
