Preheat your oven to 350°F (175°C). Grease a 1.5-quart baking dish.

Cook the jumbo pasta shells in salted boiling water for 8-9 minutes until al dente. Drain and set aside.

In a large mixing bowl, combine turkey, mashed potatoes, celery, onion, garlic, and half of the cheddar cheese. Season with salt and pepper.

Spread ¾ cup of gravy on the bottom of the baking dish. Stuff each pasta shell with the filling and place in the dish.

Drizzle the remaining gravy over the stuffed shells and sprinkle with the rest of the cheddar cheese.

Bake for 25-30 minutes until the cheese is melted and bubbly.

Let cool for a few minutes before serving. Garnish with fresh herbs if desired.