Preheat oven to 400 degrees F
Bring a pot of water to a boil and salt generously.
While the water comes up to a boil, melt the butter in a skillet and then add the all-purpose flour.
Whisk the all-purpose flour and melted butter over medium-high heat for about 2 minutes.
Add the milk and whisk to remove any lumps.
Cook over medium-high heat until the sauce thickens.
While the sauce is thickening cook the macaroni according to packaging instructions.
Once the sauce thickens, stir in 3/4's of the 4 different kinds of cheese, leaving some behind for later.
Season the cheese sauce with salt and granulated garlic.
Add the dry mustard.
When the pasta is almost done cooking, drain it and add it to the cheese sauce.
Place the macaroni and cheese sauce in a greased casserole dish and top it off with the remaining 4 kinds of cheese.
Add truffle oil and buttered breadcrumbs if desired.
Bake for 20-25 minutes.