Double-Cheese Potato Gratin

Our test kitchen director used a food processor with a slicing attachment to cut the spuds into rounds in seconds.

Ingredients

• ½ stick butter
• 1 Tbs. flour
• 2 cups milk
• 1 Tbs. minced fresh thyme
• 4 baking potatoes, peeled and sliced into ¼”-thick rounds 
• 1 cup grated Parmesan cheese
• ½ cup grated Gruyère cheese
• 1 bunch fresh chives, sliced

Instructions

1. Heat oven to 400°F. In pan over medium heat, melt butter. Whisk in flour; add milk. Let simmer 5 min. or until thickened, whisking. Add thyme.
2. Spread ¼ potato slices in bottom of 9″ x 13″ greased casserole dish. Ladle ½ cup milk mixture over top; sprinkle with ¼ cup Parmesan and 2 Tbs. Gruyère. Repeat layering 3 times. Cover with foil; bake 1 hr., uncovering during last 10 min. Top with chives.