6 large yukon gold potatoes, peeled and sliced thin
Top with herbs of choice: thyme, scallions, parsley
Pre-heat the oven to 400°F. Grease an 8" casserole dish with butter and set aside.
In a large pan, melt 1 tablespoon of butter over medium heat. Add onion and cook until onion is translucent and starting to soften, about 5 minutes. Add remaining tablespoon of butter, arrowroot, salt, pepper, garlic powder, onion powder, thyme and paprika and stir together until melted.
Slowly whisk in milk, a half cup at a time until completely combined. Increase heat to medium and cook for 10 minutes, stirring occasionally until the sauce has darkened in color and thickened.
Remove from the heat and stir in the 1-3/4 cups cheddar cheese until melted. Add sliced potatoes and mix to combine.
Pour in the casserole dish, and smooth down. Top with remaining cheddar cheese and bake for 40 minutes uncovered, until the potatoes are cooked through and a knife can easily be inserted.
Top with herbs of choice: thyme, scallions, parsley and serve warm!
Alternatively, you can cook this in a large oven-safe skillet and make the casserole directly in the skillet, as shown in the photos.