In a large mixing bowl, combine the ground turkey, panko breadcrumbs, grated Parmesan, egg, chopped onion, minced garlic, fresh sage, dried thyme, salt, and black pepper. Mix gently until combined.

Using your hands or a cookie scoop, shape the mixture into 1.5-inch meatballs and place on a parchment-lined baking sheet.

Heat a large skillet over medium heat and drizzle in some olive oil. Gently add the meatballs, searing them for 2-3 minutes on each side until golden brown.

In the same skillet, add more olive oil if needed and cook the chopped onion for 5-7 minutes until translucent. Add minced garlic and sauté for an additional minute.

Stir in the pumpkin puree, chicken broth, heavy cream, fresh sage, dried thyme, and nutmeg into the skillet. Whisk until smooth and let simmer.

Reduce heat to low and allow sauce to simmer for 10-15 minutes, stirring occasionally.

Taste the sauce and adjust seasoning with salt and black pepper as needed.

Gently add the browned meatballs into the sauce, ensuring they are well coated.

Cover and let the meatballs simmer in the sauce for 15-20 minutes or until they reach an internal temperature of 165°F.

Remove from heat and serve the turkey meatballs in pumpkin sage sauce over your preferred base.