Ingredients
- 1 clove garlic
- 1 tablespoon butter, softened
- 1 large onion, peeled
- 2 tablespoons olive oil
- 2 cups milk
- 1/2 teaspoon fresh thyme leaves
- 1/2 cup heavy cream
- 2 tablespoon butter
- 3 tablespoons all-purpose flour
- 5 medium russet potatoes
- 1 medium sweet potato
Preparation
Step 1
1. Preheat oven to 350 degrees. Rub inside of a 2 1/2 to 3 qt. gratin dish with garlic clove, cheat with the 1 tablespoon butter.
2. With a mandolins, slice onion about 1/16 inch thickness. In a skillet over low heat cook onion in olive oil until tender, sprinkling with salt and pepper. Remove from heat, stir in thyme leaves. Set aside.
3. In a small saucepan heat milk and cream just until simmering. In a saucepan, melt the butter over medium heat. Whisk in flour. Remove from heat and whisk in hot milk and cream a little at a time. Return to heat, bring to a gentle boil. Cook 3 to 5 minutes until well thickened.
4. Peel all potatoes. With a mandoline, slice potato to 1/16 inch thickness. Lay one-third of the russet and sweet potato slices in prepared dish. Season with salt and pepper. May add a light grating of nutmeg.
5. Scatter about one-third of onions on potatoes. Spoon one-third of cream mixture of potatoes. Create two more layers with remaining potatoes, seasonings, onions and cream mixture, finishing with cream mixture on top. ( Cream may not totally cover the top.)
6. Bake, uncovered, 45 minutes. Increase oven temperature to 425 degrees. Bake 10 to 15 minutes more or until bubbly, golden, crusty brown and potatoes are tender. Remove from oven. Let stand 10 minutes. Makes 8 servings.