Start by pulsing the celery, onion, carrots, thyme, sage, salt, and black pepper in a food processor until finely chopped.

Heat 2 tablespoons of olive oil in a skillet over medium heat. Add the finely chopped vegetable mixture and sauté for 10-12 minutes until softened and fragrant.

Preheat your oven to 425°F (220°C).

In a large mixing bowl, blend together 3 cups of bread flour, 2 tablespoons of baking powder, 1 teaspoon of baking soda, and 1 teaspoon of granulated sugar.

In a separate bowl, whisk together 1 cup of buttermilk and 4 tablespoons of melted unsalted butter until fully combined.

Gently fold the wet mixture into the dry ingredients until just combined; the dough should remain a bit shaggy.

Using a spoon or cookie scoop, drop heaping spoonfuls of dough onto the prepared baking stone or lined baking sheet.

Bake the biscuits in the preheated oven for 12 minutes.

In a small bowl, mix the remaining melted butter with 1 tablespoon of chopped fresh rosemary. Brush the tops of the biscuits.

Return the biscuits to the oven and bake for an additional 6-8 minutes until golden brown and flaky.

Allow the stuffing biscuits to cool slightly on the baking sheet before serving.