Grate all your cheeses and toss together, set aside. Warm milk: either on the cooktop or in the microwave, just warm, not hot. Set aside. Set a large pot of salted water on high heat. This is for your pasta. While water heats, make cheese sauce.

In a medium sized saucepan on medium heat melt butter, add salt and pepper. Add flour to melted butter and whisk. This is your roux, it will thicken your cheese sauce.

Very slowly drizzle warm milk into the roux, continually whisking and heat until mixture begins to thicken. When milk is thickened, add cheese a handful at a time, whisk in between additions, slowly adding more as each handful melts.

When cheese is completely melted and sauce is smooth turn off heat.

Add gnocchi to boiling pasta water and cook to package instructions. (I use a fresh gnocchi that cooks in three minutes). Strain, do not rinse. Place in a bowl and pour the cheese sauce over. You can use all the sauce or less, depending on how cheesy you like it. Enjoy!