1To make the pastry dough: Place the flour in a large bowl, make a well in the center and add the butter, egg, milk and pinch of salt. Blend the ingredients inside the well with a fork; the butter should still be lumpy. Gradually start to pull the flour in from the sides. Once incorporated, turn the dough onto a floured working surface. Gently knead until the mixture forms a ball. Wrap in plastic, ad refrigerate for at least 1 hr.
2Preheat oven to 400 F.
3In a large pot of boiling water, add salt to taste. Place the asparagus into the pot and cook just until tender, about 5 minutes. Drain and place the asparagus into a bowl of ice cold water. When cool, drain.
4Make a roux by melting the butter in a small saucepan over medium heat. Add the flour and stir until dissolved. Remove from heat, and let cool.
5Cut off the asparagus tips and set aside. Trim the stems into ¾ inch pieces and combine in a bowl with the ricotta, Parmigiano Reggiano, roux, and nutmeg. Season with salt and pepper. Mix in the beaten eggs.
6On a floured working surface, roll out 2/3 of the dough into an 11 inch round, 1/8 inch thickness. Line a9 inch tart tin with the dough. Trim the excess dough and prick the bottom with a fork. Spread the filling evenly over the dough and top with the asparagus tips.
7Roll out the remaining dough into a square, cut the sough into 1/4inch wide strips using a pastry wheel. Arrange the strips over top the filling in a lattice pattern.
8Bake for 25-30 minutes or until puffed and golden. Cool 10 minutes before serving.