Asparagus, Gruyere, and Pancetta Slab Pie

My first slab pie!  Pie Squared is the Food 52 Baking Club book of the month this month and if this is any indication, it is great.  I made this with a butter crust but the book suggests a lard one.  I just didn't have lard, and I am not a slave to following a recipe exactly.  It was delicious!

Filling:

 1 lb (450 gm) fresh asparagus
1 c. (225 gm) diced pancetta
5 large eggs
1/2 c. (120ml) cream
1/2 tsp. kosher salt
8 oz. (225 gm) fontina cheese
1/2 c. (50 gm) sliced scallions
herbs and pepper to taste

Butter Crust:

1 1/2 c. (160 gm) all purpose flour
8 Tbs. (113 gm) cubed butter
dash of salt if using unsalted butter
1/4 c. (60 ml) ice water

For the crust:
Ideally, weigh the ingredients.  Put the food processor bowl on the scale and weigh the flour, then the butter.  Use the blade and pulse about 15 or so times to cut the butter into the flour, leaving the butter in pea sized pieces.  Add the ice water all at once, and pulse until dough comes together, just barely.  Lay out a piece of plastic wrap and dump dough onto it.  Try not not handle it, using a bench scraper instead of your hands to form it into a rectangle.  Wrap and then use a rolling pin to get it into a thinner slab.  Refrigerate at least an hour and can stay there for days.
To bake, roll out to the size of a 1/4 cake sheet pan size, crimp the edges, and blind bake at 350 degrees for 20 minutes.  Remove pie weights, and assess, can put back in oven 5 more minutes to dry out.

For the filling: trim asparagus, shaving off the tough outer skin if it is not tender.  Dice the pancetta and saute until crisp.  Whisk the eggs, cream, salt and seasoning until well mixed.  Scatter the pancetta evenly across the pan, lay the asparagus on top of it alternating tops to bottoms.  Add 1/2 the cheese, add the egg mixture, and bake at 400 degrees for 25-30 minutes on top of a pizza stone, or a steel slab.  This is the key to no soggy bottoms.