Press the mixture on the bottom and sides of a springform cake tin which has been lined in baking paper. refrigerate.
blanche the asparagus for 12-20 minutes in boiling salted water. Chop them but leave about 12 spear heads to decorate the top.
Saute the onions, add the asparagus then add the cream add cook for a few minutes.
Mix the crumbled or grated cheese with the ricotta and the remaining 2 eggs. Then add half the parmesan and the asparagus mix. season with salt and pepper.
Pour the mixture into crust and bake at 180C for about 1 hour. Dust with the remaining parmesan and brown under a grill. serve warm not hot.