Line a baking sheet with parchment paper.

In a large saucepan, whisk the milk with the salt and bring just to a boil.

While whisking constantly, slowly add the semolina in a steady stream until smooth.

Cook over moderate heat, whisking constantly, until slightly thickened, about 1 to 2 minutes.

Remove the pan from the heat and whisk in 6 tablespoons of the butter until incorporated.

Add 1 cup of the cheese and the egg yolks and stir with a wooden spoon until well blended.

Scrape the semolina mixture onto the prepared baking sheet and spread in an even layer about 3/4 inch thick.

Refrigerate until completely cooled, about 1 hour.

Preheat the oven to 350°F (175°C).

Butter a 2 1/2- to 3-quart baking dish.

Using a 2 1/2-inch round cookie cutter or wineglass, cut the semolina dough into rounds as close together as possible.

Reserve the scraps for another use.

Arrange the rounds in the prepared dish, overlapping them slightly.

Cube the remaining 2 tablespoons of butter and scatter over the top.

Sprinkle the remaining 1/2 cup of cheese over the gnocchi.

Bake for about 30 minutes, until they are golden brown and hot throughout.

Serve warm.