Asparagus, ham and mushrooms are a great combination in a quiche! Serve with a crisp green salad. If the asparagus tips are thick - you can cook them for a few minutes before arranging them in the pastry case.
Preheat oven to 220 C / Gas 7. Lightly grease and flour a 20cm pie tin.
Arrange shortcrust pastry in prepared tin; cover the pastry base with foil, pressing it down firmly and bake for 10 minutes in preheated oven. Remove the foil and allow the tart to cool down.
Melt 2 tablespoons of the butter in a wide pan over medium heat; add onion, ham and mushrooms and cook until onions have softened, about 3 to 5 minutes. Season to taste with salt and pepper.
Combine flour and remaining 2 tablespoons butter in a saucepan over medium low heat; add milk, stirring continuously, until smooth and thick. Add grated nutmeg; remove from heat and whisk in egg yolk and cream.
Spoon ham and mushroom mixture into pastry case; arrange asparagus tips in an even layer on top. Pour sauce on top and add grated cheese.
Bake in preheated oven for 15 to 20 minutes until filling is set and the top is golden brown.