1 cup full-cream milk, at room temperature or warmed
100g Parmesan, grated
4 free-range eggs, at room temperature, separated
Salt and milled pepper, to taste
Method
Preheat the oven to 220°C.
Halve the squashes and scoop out the seeds. Steam over boiling water until tender.
In a saucepan, melt the butter, stir in the flour, then gradually stir in the milk and cook, stirring, until thick and smooth. Add the grated cheese and stir until melted.
Remove from the stove and beat in the egg yolks, one at a time. Season.
Beat the egg whites until stiff peaks form.
Fold a third of the beaten egg whites into the cheese sauce, then fold in the remaining beaten whites.
Arrange the gem squash halves on a baking tray and fill with the cheese-egg sauce.
Bake for 10 minutes or until puffed, golden and just set.