Gather and prep ingredients. Preheat the oven to 425°F. Line a large sheet pan with foil or parchment.
In a large bowl, toss carrots, sweet potato, yellow potato, parsnips, and onion with oil, salt, pepper, garlic powder, poultry seasoning, and dried rosemary. Spread evenly on the sheet pan.
In a medium bowl, combine ground turkey, cottage cheese, panko, onion, parsley, garlic powder, salt, pepper, poultry seasoning, and Worcestershire. Mix until just combined; the mixture will be soft. (see notes)
Using a spoon or small scoop, form 1½-inch meatballs (about 20 total). Nestle them evenly among the vegetables on the sheet pan. Roast in the oven for 20 minutes.
While meatballs roast, melt butter in a small pan or microwave-safe bowl. Stir in minced garlic, maple syrup, and Dijon mustard.
Brush or drizzle the maple-garlic glaze over the meatballs and vegetables. Return to the oven for 10-12 minutes more, until meatballs reach 165°F and vegetables are tender and caramelized.
Spoon any extra pan juices over the meatballs and vegetables when serving. Enjoy!
*I use 85% lean ground turkey. That little bit of extra fat adds flavor and helps keep the turkey meatballs juicy as they roast. Leaner ground turkey will still work, since the cottage cheese adds moisture, but the finished meatballs may be slightly less rich.**Panko breadcrumbs have larger, airier flakes, which helps bind the mixture without making the turkey feel too heavy or compact. You can also use regular breadcrumbs. Just note the mixture may feel a little firmer once combined.***I use poultry seasoning in both the meatballs and the root vegetables so the same savory herb flavor carries through the whole pan. Most blends include herbs like sage, thyme, and rosemary, which pair especially well with turkey and the sweet maple-Dijon glaze. You can use any store-bought option or make your own homemade poultry seasoning for more control over the flavors!
Turkey Mixture: The meat mixture will be soft due to the cottage cheese. Handle gently to avoid overworking (which can make the meat tough and dense!) Mix until just combined.
Make Ahead: For a head start on dinner, you can mix and shape the turkey meatballs a few hours ahead before cooking. Arrange them on a plate or tray, cover tightly, and keep refrigerated until you’re ready to add them to the sheet pan.