Step 1

Preheat oven to 400 degrees. Line the baking sheet with parchment paper.

Step 2

Grate 8 tablespoons of the butter on a box grater. Transfer to a plate and stick in the freezer while you prep everything else.

Step 3

Melt remaining two tablespoons butter in a small skillet over a medium heat. Add celery and shallot. Sweat the veggies until they start to soften, about 5 minutes. If they every start to brown, turn the heat down to medium low. After they have softened add the sage and two teaspoons of poultry seasoning. Cook until the sage is fragrant. Remove from the heat and transfer to a small bowl. Cool completely.

Step 4

While the butter chills and the veggies cool, mix the dry ingredients. Add flour, baking powder, baking soda and salt together in a large bowl. Set aside.

Step 5

When the veggies are cool. Add them to the flour mixture. Stir to combine. Add the frozen butter. Stir to combine. Drizzle buttermilk over the flour mixture while stirring to evenly incorporate. Once the dough comes together, dump on a lightly floured surface. If there are still some scraps, gently knead the dough to bring everything together.

Step 6

With a lightly floured rolling pin, roll out the dough until it's about 1/2 inch thick. Fold the dough in half and roll out again. Repeat one more time and then roll out the dough until it's 3/4 inch thick.

Step 7

Lightly dust a 2 1/2 inch biscuit cutter. Cut the dough into biscuits. Be sure you go straight down and straight back up. This will ensure the biscuits rise evenly. Place in the fridge to chill for 10 minutes.

Step 8

Add egg and 2 tsp water to a small bowl. Place the chilled biscuits on the baking sheet. Brush with egg wash. Bake in the oven for 12-15 minutes or until the tops are golden brown and the biscuits have risen. Eat right away or at room temp.