Cheesy mashed potato biscuits

Preheat oven to 400F. Grate 1/2 stick of butter. Want long, thin strands to help the biscuit be flaky. Put the grated butter in the freezer. Shred/grate 3/4 cup of cheese. In a large bowl, whisk together 2 1/3 cups all-purpose flour, 2 tsp salt, and 1 tbsp baking powder. Gather up whatever herbs you have and finely chopped enough to get tbsp. Add to the bowl and whisk. Add the cheese and whisk. Add the chilled, grated butter to the dry ingredients and toss lightly just until the butter is coated in flour. Add 1 cup mashed potatoes and continue tossing lightly until the potatoes have broken down into pea-sized pieces. There's not reason to worry about using seasoned, super fatty, or plain mashed potatoes. Using your hands, make a well in the middle of the ingredients. Fill the well with 3/4 cup buttermilk. Slowly mix the ingredients together until a dough forms. Turn the dough out onto a floured surface and pat down into a 10 inch circle. To cut the biscuits, use a 3-in biscuit cutter (or empty soup container) and cut 10-12 biscuits. Place the bisuits into a 10-in cast iron pan. Brush the bisuits with buttermilk on top. Sprinkle with some cheese, herbs, and/or pinch of black pepper. Bake the biscuits for 20-25 minutes or until they've doubled in size and are golden brown on top.