Create a roux by warming the two tablespoons of butter in a large skillet and adding the one tablespoon of flour. Mix well until all of the flour is incorporated.
Slowly add in the milk. Once the flour, butter and milk have combined, add both the Fontina and Gruyere cheeses. I myself had to shred more cheese at this point, as someone had been nibbling on it. Yes, I mean you Franny!
At this point, the sauce should be fairly thick. If you wish for it to be thicker, bring the cheese sauce to a slight boil and then remove it from the heat. If you want to thin it out a bit, add more milk. But do it sloooowly.
In a large mixing bowl, toss the cooked gnocchi with the cheese sauce so that it is fully covered. If you want to eat one or two, I won’t tell.
Transfer the cheese-covered gnocchi to a baking dish large enough to spread it out into a single layer. Then lightly top it with parmesan cheese and bread crumbs.
Bake the dish at 350 degrees for about 20 minutes, until the cheese sauce begins to boil and becomes golden.
Let the dish cool for a few minutes before serving. Enjoy!