Preheat your oven to 375°F (190°C) and liberally spray a 12-cup muffin pan with non-stick cooking spray.

Using a mandoline or a sharp knife, thinly slice your peeled russet potatoes to about 1/16 inch thick.

In a large mixing bowl, combine melted unsalted butter, olive oil, minced garlic, fresh thyme, rosemary, fine sea salt, and freshly ground black pepper.

Add the thin potato slices to the bowl with your herb mixture, tossing gently until every slice is evenly coated.

Begin layering the potato slices vertically in the muffin cups, stacking them until they rise just above the rim. Drizzle any remaining herb mixture over the tops.

Place your muffin pan in the preheated oven and bake the galettes for 45-50 minutes, rotating the pan halfway through.

After baking, allow the galettes to cool in the pan for about 5 minutes. Carefully use a fork or small spatula to lift each galette out.

Finally, garnish your galettes with fresh sprigs of thyme and rosemary before serving.