Preheat the oven to 350 degrees F and lightly grease an 8x8 pan (or 8-inch round baking dish or cast iron skillet) with nonstick cooking spray.

Add the potatoes to the pan– you can either stand them up in a line or just throw them in! 

Heat a large saucepan over medium heat.

Add the butter and allow it to melt. Next, add the garlic and thyme and cook for 1 minute. 

Sprinkle over the flour and whisk until roux forms. Cook the roux for 1 minute. 

Slowly add the milk, whisking constantly. Continue whisking until no large lumps remain. 

Cook the bechamel until it has thickened enough to coat the back of a spoon– about 3 minutes.

Next stir in ½ cup cheddar, ½ cup gruyere, and the nutmeg. Stir until the cheese has melted. 

Taste and season the bechamel with kosher salt and freshly ground black pepper as needed. 

Pour the bechamel over the potatoes– if you stood the potatoes up in a line, make sure to spread the sauce between the potatoes and along the edges of the pan– we don’t want it to just sit on top of the potatoes! If you added the potatoes to the pan in a pile, give them a gentle stir to incorporate the bechamel with the potatoes. 

Cover the scalloped potatoes with foil and bake for 50 minutes.

Remove the pan from the oven and sprinkle over the remaining shredded cheddar and gruyere and the breadcrumbs.

Return the pan to the oven and bake for an additional 40-50 minutes, or until the top is golden brown and the potatoes are fork tender. 

Garnish with fresh parsley or chives and enjoy.