in a large bowl, mix flour, butter, milk, and salt until well
combined. wrap in plastic wrap and refrigerate for one
hour. roll out large enough to overhang a buttered tart pan
by at least 1.5 inches. push dough into the pan carefully
and dock with fork tines. blind bake in a 400F oven for 25
minutes. meanwhile, mix eggs, heavy cream, poppy seeds,
and horseradish in a bowl. (when you think you've added
enough horseradish, add 25% more. trust me.) mix until
well combined and season with salt and pepper. pour egg
mixture into crust and bake until cooked through and golden.
sprinkle some grated parmesan cheese on during the last few
minutes of cooking. cool and slice.