Line a 9-inch pie plate with the pastry dough. Flute edge and prick bottom in several places with tines of a fork. Line crust with foil and fill with beans, rice, or other pie weight. Bake in a 400° preheated oven for about 8 minutes.
Remove foil and weight and bake 2 to 3 minutes longer. Remove from oven; reduce oven temperature to 375°.
In a skillet over medium heat, sauté onion in the butter until tender; transfer to the pie shell. Top onions with crab and dill. Combine eggs, wine, salt, pepper, and cream; pour over crab mixture in shell. Bake crab quiche at 375° for 25 to 30 minutes, or until set.