I had a huge head of Cauliflower, so I wanted to make a gratin and decided to try this one:
http://www.arla.dk/opskrifter/blomkalsgratin/

It is in Danish, but I can give you a rough idea of what to do. (I don’t eat meat, so I left out the smoked ham and used a bit more Cauliflower instead).

500 g Cauliflower
Water for cooking the cauliflower
Salt

90 g flour
300 ml milk
10 g butter
4 egg yolks
1 tsp salt
Pepper
4 egg whites

Butter and bread crumbs for the tray

……………

Set the oven to 175 degrees Celsius.
Grease a tray with butter and line it with bread crumbs.

Divide the Cauliflower into pieces and cook in lightly salted water for 4 min.
Drain water.

Melt butter with milk in casserole and stir in flour while boiling.
Set aside to cool a bit.
Stir in egg yolkes one at a time.
Add salt and pepper.

Whip the egg whites stiff.

Add half of the whipped egg whites to the filling together with the drained Cauliflower and stir.

Fold in the rest of the whipped egg whites.

Spread filling evenly in the tray/form and place in oven to cook for approximately 1 hour.

……
Some photos 🙂