Preheat the oven to 400°F.

In a small saucepan, melt 4 tablespoons of the butter and add rosemary and thyme.

Remove from heat and set aside to infuse.

In the bowl of a food processor, pulse both flours with the sugar, baking powder, salt and soda.

Dice remaining butter and add it to the flour.

Pulse until mixture resembles coarse crumbs.

Transfer mixture to a mixing bowl. (Alternatively, stir the ingredients together in a large mixing bowl. Use a pastry blender to cut the butter into the flour mixture.)

Stir in the sage leaves followed by the buttermilk.

Mix just until combined.

Line a baking sheet with parchment paper.

Drop tablespoons of dough onto the sheet in 12 even mounds.

Brush the tops with the reserved herb butter.

Bake the biscuits until golden brown and fragrant, 15 to 20 minutes. Cool on a wire rack for a minute or two before serving.