Preheat the oven to 400°F (200°C) and line a baking sheet with parchment.
Make the panade: stir the panko and milk together; let sit 5 minutes.
Add the chicken, egg, Parmesan, garlic, parsley, Italian seasoning, salt, pepper, and nutmeg. Mix gently with your hands just until combined.
Scoop into 1.5-inch meatballs (about 24) and place on the sheet.
Bake 18–20 minutes, until cooked through (165°F / 74°C internal).
Cook the pasta to al dente in salted water; reserve ½ cup pasta water before draining.
Melt butter in a large skillet over medium-low. Add garlic and cook 30–60 seconds until fragrant.
Pour in the heavy cream and bring to a gentle simmer.
Lower the heat and whisk in the Parmesan a little at a time until smooth. Season with pepper, nutmeg, and salt to taste. Loosen with pasta water if needed.
Add the baked meatballs to the sauce and turn gently to coat. Simmer 2–3 minutes.
Serve over fettuccine, garnish with parsley and Parmesan, and enjoy.