Place the milk, 50 grams (1 3/4 ounce) of the butter, the salt and nutmeg in a saucepan over high heat and bring to a boil.
Working quickly, pour the semolina flour into the pan in a continuous stream, whisking constantly to avoid lumps forming.
Reduce the heat to medium and continue whisking for 3-4 minutes.
As the mixture thickens, replace the whisk with a wooden spoon and continue stirring until a dough forms.
Remove from the heat, add 80 grams (2 3/4 ounces) of the parmesan and stir to incorporate.
Next, add the egg yolks one at a time, beating thoroughly into the mixture before adding the next.
Line a 33 centimeter x 23 centimeter (13 inch x 9 inch) baking dish with baking paper, then using a spatula, spoon and smoothly spread the semolina mixture into the dish to a depth of about 1.5 centimeters (1/2 inch).
Set aside for 40-60 minutes to completely cool and set.
Preheat the oven to 200˚C (400˚F).
Using a 5 centimeter (2 inch) round pastry cutter, cut the semolina into 16 discs.
Grease a large baking dish with 10 grams (1/4 ounce) of the remaining butter and lay the discs in slightly overlapping rows.
Dot the gnocchi with the remaining butter, sprinkle over the remaining parmesan and season with black pepper and extra nutmeg.
Bake for 20-25 minutes, until golden and crisp.
Divide the gnocchi among warmed plates and serve immediately.