Wash hands, Preheat oven to 400*. Get all tools and ingredients out.
Line a baking sheet with parchment paper.
In a small bowl, whisk together the egg yolk and milk until smooth.
In medium bowl, whisk together flour, baking powder and salt and garlic salt.
Grate cheese and butter into flour mixture. Toss with spatula to coat.
Make a well in center of flour mixture and pour wet mixture into hole.
Using a spatula, combine the wet and dry, JUST until the dry is wet and there is no more dry flour.
Using a large cookie scoop, scoop into 8 rounds onto baking sheet.
Place baking pan in oven, and set timer for 18 minutes.
Check biscuits for doneness, and remove to cooling rack.