Pre-heat the oven to 425°F.
Bring water to a boil in large pot for the pasta. When the water boils, wait until the meatballs go into oven. When the meatballs have been in the oven for 4-5 minutes, season the water with salt, add the spaghetti and cook to al dente. Drain the pasta and keep warm.
Soak the stuffing with about 1 cup stock in small bowl until softened, a couple of minutes.
Place the turkey in a mixing bowl and season with salt and pepper. Add the apple, lemon juice, celery, onion, poultry seasoning, egg and stuffing and mix until just combined.
Line a baking sheet with parchment paper. Form the meat mixture into 16 2-inch balls, drizzle with some EVOO and roast until cooked through, firm and golden, about 12 minutes.
While the meatballs roast, heat a couple of tablespoons the EVOO in a large skillet. Add the mushrooms and thyme and cook over medium-high heat until tender; season with salt and pepper. Make a well in the center of the pan and add the butter; when melted, whisk in the flour. Cook for 1 minute, then whisk in about 2 cups stock and the Worcestershire sauce. Reduce the heat to low and cook for a few minutes to thicken the sauce, then stir in the cream or half-and-half.
Toss the pasta in a large serving bowl with the meatballs, sauce and cheese. Garnish with parsley and serve.