Preheat oven to 425° with the rack in the center position. Bring chicken stock to a simmer in a small saucepan and reduce to 2 cups, 25–30 minutes.
In a medium skillet, melt butter over medium heat until foamy, add celery, onion, carrot, and garlic, and sauté 10–12 minutes until vegetables are slightly soft and onions are translucent. Remove from heat and transfer mixture to a large bowl. Mix in parmesan, almond meal, and herbs until thoroughly combined. Crumble in chestnut purée and mix well to incorporate, season lightly with salt and pepper.
Rinse turkey breast and pat dry with paper towels. Lay skin-side down on clean work surface and, if needed, slice butterfly-style to create a larger surface area. Season interior liberally with salt and pepper. Spread filling mixture evenly over surface, leaving 1" border at edges. Starting at shortest edge, gently roll breast up and over stuffing. Place seam-side down and tie securely with kitchen twine. Season outside of breast liberally with salt and pepper.
Wipe out skillet and heat olive oil over medium-high heat. Brown turkey breast on all sides until golden brown, 10–12 minutes. Transfer breast to a foil-lined rimmed tray or small roasting pan and roast 12–15 minutes per pound until interior temperature in thickest part of breast registers 155°. Remove from oven, tent loosely with foil and rest 15 minutes.
While turkey roasts, add wine to hot skillet and reduce by half, scraping up any brown bits in the pan. Add reduced stock and bring to a simmer. Mix potato starch with 2 tbsp. cool water to form a slurry and whisk into simmering stock. Simmer, stirring constantly, 2–3 minutes until mixture has thickened. Remove from heat, strain gravy through a fine-mesh sieve and season to taste. Untie turkey breast and slice crosswise into 1 1⁄2"–2" slices. Serve with gravy.