Sauté leeks in olive oil over medium-high heat for 8 minutes or until tender. Transfer to a large bowl; stir in halibut and next 9 ingredients. Set aside.
Combine 2 cups flour, wheat germ, and salt in a bowl. Cut in shortening with a pastry blender until the size of small peas. Sprinkle cold water, 1 tablespoon at a time, over surface; stir lightly with a fork just until dry ingredients are moistened. Shape pastry into a ball, and divide into 2 portions. Roll 1 portion to 1/8-inch thickness on a lightly floured surface. Place in a 9-inch pie plate.
Roll remaining pastry to 1/8-inch thickness. Spoon halibut mixture into prepared crust; place pastry over filling. Trim off excess pastry along edges, fold edges under and crimp. Cut slits in top crust to vent.
Bake at 450° for 10 minutes. Reduce temperature to 350°, and bake for 40 minutes or until golden. Let stand 10 minutes before serving.
Wine note: This is a pie for Chardonnay lovers. I recommend one from the Burgundy region of Chablis. Most of these are oak-free with bright acid and great minerality to cut through the richness of the sauce and accent the earthiness of the potato. Any Louis Michel Premier Cru such as Grenouilles ($25-$44) would be heaven.--Steven Geddes