In a medium bowl, cut shortening into flour and salt (optional) until crumbly
Add in milk slowly and incorporate by hand
Turn out dough, once it comes together, on a floured board and knead in additional flour as needed to bring the dough together and ensure it is not sticky.
Roll out to about ½ inch thick and cut using a biscuit cutter or glass
Transfer to a cast iron skillet and allow to rest while oven comes to temperature. About 5 minutes
Preheat oven to 425° and bake biscuits for 15 to 20 minutes until golden brown and fluffy.