Procedure

1. Preheat the oven on broil. Bring a pot of water to a boil and season with salt. Cook the pasta 1 minute short of the package directions.
2. Heat a large heavy bottomed pot over high heat. Add 3 tablespoons of olive oil and add cauliflower, tossing to coat. Season with salt and pepper and cook for 5 to 6 minutes until the cauliflower begins to caramelize.
3. Add the butter to the pot. Whisk in flour to form a paste. Season with salt and cook for 2 to 3 minutes just until the paste starts to take on a warm golden color. Whisk in the milk and season with salt, pepper, nutmeg and chili flakes. Stir in the gruyere and half of the Parmigiano-Reggiano to melt. Add in the ham. Add the cooked pasta and stir to coat. Transfer to a greased baking dish.
4. Mix the bread crumbs, remaining cheese and chopped parsley. Sprinkle evenly over the pasta and place under the broiler. Cook for 2 to 3 minutes, just until the bread crumbs are golden brown.