Sift flour, sugar, and salt into a mixing bowl. Stir grated Cheddar cheese into the flour mixture using a fork. Stir in butter using a wide spoon until mixture becomes crumbly. Set topping mixture aside at room temperature.

Preheat the oven to 400 degrees F (200 degrees C). Place pie crusts in their tins onto a baking sheet to catch drips; place crusts 1 inch apart.

Sift sugar, cornstarch, and salt into a small bowl. Place pears in a large mixing bowl. When oven is hot, sprinkle sugar mixture over pears and stir to combine. Pour filling evenly into the 2 pie crusts. Divide topping mixture in half and add to the top of each pie in 4 to 6 dollops; use a wide knife to spread evenly.

Bake on the middle rack of the preheated oven for about 18 minutes; the pears will produce a lot of liquid and will bubble over. Check pies and cover with aluminum foil if crust or topping is getting dark. Bake about 7 minutes more.