Cook pasta until al dente; drain and set aside.
Dice chicken and ham, mince garlic, and measure ingredients.
Melt butter, add garlic, and sauté until fragrant.
Add flour; whisk 1–2 minutes to create roux.
Slowly whisk in milk and cream; simmer until thickened.
Stir in cheese, Dijon, salt, pepper, and nutmeg until smooth.
Add chicken, ham, and pasta to sauce; toss to coat.
Transfer to baking dish, top with buttered breadcrumbs and Parmesan.
Bake 15–20 minutes at 375°F until golden and bubbling.
Rest 5 minutes, garnish with parsley, and serve warm.