Combine flour, salt, and butter in a food processor or a blender. Pulse until mixture resembles coarse crumbs. Though a food processor will work much better, I did use my blender. It took longer, but it worked.
Mix the ice water and apple cider vinegar in a small bowl.
Pour 1/2 the water mixture in a blender; pulse 3 times to blend. Pour the rest in the blender and pulse 8 more times, until all comes together.
Turn dough out onto a wooden surface or on parchment paper, and kneed for a couple of seconds, then divide in half. Wrap each piece in plastic wrap and place in the refrigerator for 30 mins.
When ready to use, fold and press the dough into the desired shape and place one in the bottom of a dish (I used a ceramic pie dish), fill with vegetable filling, then top with the other piece of dough
Using bottom rack, bake on a cookie sheet on 450 degrees for 45 mins to 1 hour. Watch it after 45 mins. It may need more time to bake. Mine did.