Using your fingers, work the shortening in with the flour in a large bowl until the flour appears crumbly, about the size of little peas. Stir in the buttermilk & shredded cheddar with a wooden spoon.
Lightly dust your countertop with a little flour.
Pat the dough down into a neat rectangle, no reason to do any kneading really. Using a pizza cutter, slice the biscuits into 8-10 squares. Place the biscuits into a greased cast iron pan or if you don't have one, a round cake pan or any casserole dish will do, with the sides of the biscuits just touching.
Melt 4 tablespoons of the butter and stir in the tablespoon of garlic powder and garlic salt. Pour on top of the biscuits. Bake for 15 minutes, or until nicely browned.
Melt the rest of the butter. Add the teaspoon of garlic powder and stir. Brush the mixture on top of the biscuits once they come out of the oven.