Preheat the oven to 350 degrees F. Grease a 9x13-inch baking dish well and set aside.

In a large dutch oven, bring 4 quarts of water to a boil. Break the spaghetti in half, and place in the water. Cook for 5 minutes, stirring often. 

Drain the spaghetti into a colander and set aside. Return the stock pot to the stove.

Over medium to medium-high heat, melt the butter.

When the butter is melted, whisk in the flour and let it cook for 1 minute.

Add garlic and cook until fragrant, about 30 seconds.

Slowly whisk in milk and chicken broth. Cook, stirring constantly, until mixture starts to bubble. Cook for 2 minutes.

Remove from heat and whisk in parmesan and 1/2 cup of grated swiss/mozzarella. When cheeses are melted, stir in the turkey, salt, and pepper.

Add the cooked noodles to the mixture. Add additional salt and pepper to taste.

Transfer all of the cheesy goodness to the prepared 9×13-baking dish. Top with the 2 cups of remaining cheese.

Bake at 350 degrees F. for 30 minutes, until everything is melted and bubbly.

Let the dish rest for 5 minutes before serving hot.