Preheat your oven to 375°F (190°C).

Grease a large baking dish with butter to ensure the potatoes don’t stick.

Carefully wash and peel the Russet potatoes. Using a sharp knife or a mandoline, slice the potatoes into about 1/8-inch thick rounds.

In a saucepan over medium heat, melt the unsalted butter. Add the minced garlic and sauté for about 30 seconds until fragrant.

Pour in the heavy cream, and season with salt and pepper. Stir continuously until the mixture is warm, but do not bring it to a boil.

Place a layer of potato slices in the bottom of the prepared baking dish. Pour a portion of the cream mixture over them, followed by a sprinkle of both cheddar and Parmesan cheese.

Repeat this process, layering potatoes, cream, and cheeses until you reach the top of the dish, ensuring a final layer of cheese for a golden crust.

Cover the dish with aluminum foil and bake in the preheated oven for 40 minutes.

Remove the foil and bake for an additional 15-20 minutes until the top is bubbling and golden brown.

Allow the scalloped potatoes to cool for a few minutes. Garnish with fresh herbs if desired, and then serve warm.