Line the baking pan with parchment paper (this step is optional, but it makes it easier to get the tart out when it has baked). Place 2-3 sheets of filo dough at diagonals to cover the baking pan (irregular lines are fine; the dough will be covered). Brush this layer of filo dough with melted butter. Repeat with layers of filo dough and butter until all of the sheets are used up.

Whisk together the cream, milk, eggs, cheese, salt, and pepper. Pour the mixture into the filo dough-lined pan. Gently place the asparagus spears down lengthwise in the pan, alternating green and white (we used two skinny green stalks for every white stalk). Carefully fold in all of the odd pointy ends of filo dough that are sticking out, and brush the edge of the crust all the way around with butter.

Bake at 350 degrees for 45 to 50 minutes, or until golden brown and puffy (and center is intact). Let cool for 10 minutes. Gently remove tart from pan, place on a platter, and cut to serve.