Place the currants in a small saucepan. Cover with water and bring to a boil. Allow them to boil for a minute and turn off the heat. Let them soak for about 5 minutes. Drain thoroughly and set aside. Preheat the oven to 375 degrees F. Combine flour, salt, and sugar, and cut in butter with a dough blender or 2 knives until it resembles a coarse meal. You can also use a food processor. Stir in egg yolks. Knead this mixture until smooth. This takes quite a bit of kneading (you might want to use 2 hands). Press the dough out on the bottom and sides of an 8 or 9-inch springform pan. Neatly finish the rim. In a large bowl, gently combine the pear slices with the lemon juice, spices, sugar, and currants. Carefully arrange the fruits in the crust. Dot with butter, sprinkle with sugar. Bake for about 30 to 40 minutes, or until the crust is golden. Cool and serve.