Preheat oven to 400°F.

Boil sweet potatoes and garlic in salted water until cooked and soft. Drain and mash with chicken broth, milk, sour cream, salt, and pepper.

In a large skillet, brown the ground turkey about 5 minutes; season with salt and pepper. Set aside.

Add olive oil to the pan, then sauté diced onion for 1 minute. Add chopped celery, parsnip, salt, and pepper; cook about 12 minutes until softened.

Add diced garlic and mushrooms; sauté another 3-4 minutes. Mix in flour and pepper.

Add frozen vegetables, chicken broth, tomato paste, Worcestershire sauce, rosemary, and cooked turkey. Simmer covered on low for 5-10 minutes until thickened. Adjust seasonings as needed.

Spread the meat mixture in a 9x12 baking dish.

Top with mashed sweet potatoes. Ridges can be made with a fork; sprinkle with paprika.

Bake for 30-35 minutes until golden and heated through.

Remove from oven and let cool 10 minutes before serving.