Two-Potato Gratin

By dyannucci

WHEN YOU START WITH HIGH-FLAVOR, NUTTY-INTENSE GRUYERE AND PARMIGIANO¬REGGIANO CHEESES, YOU DON'T NEED HEAVY CREAM OR BUTTER TO YIELD A COMFORTING POTATO DISH.

The indulgent "cream" sauce for this gratin is actually a low-fat white sauce made from 2% milk thickened with flour-not a speck of cream or butter in sight. The flavor gets seriously delicious when good aged Gruyere cheese, nutty and salty, melts in. Our gratin is
wildly delicious, hitting all those comforting starchy¬creamy-cheesy notes, and has roughly half the calories and 83% less saturated fat than a classic gratin.

EACH SERVING 218 cal, fat 9 grams, sat 3.5, mono 3.8 g, poly 1.3g, protein 9.3 g, carb 25.2 g fiber 2.7 g chol 18 mg iron 1.2 mg sodium 339 mg, cal 228 mg

Ingredients

• 2 medium baking potatoes, peeled and cut into 1/4 inch-thick slices (about 3 cups)
• 2 medium sweet potatoes, peeled and cut into 1/4 inch-thick slices (about 4 cups)
• 2 quarts no-salt-added chicken stock (such as Swanson)
• 2 tablespoons canola oil
• 3 tablespoons all-purpose flour
• 2 garlic cloves, crushed
• 1 1/2 cups 2% reduced-fat milk
• 2 thyme sprigs
• 3/4 teaspoon kosher salt, divided
• 1/4 teaspoon freshly ground black pepper
• 3 ounces aged Gruyere cheese, shredded (about 3/4 cup)
• Cooking spray
• 2 tablespoons chopped fresh chives, divided
• 1 1/2 teaspoons chopped fresh thyme
• 1 ounce fresh Parmigiano-Reggiano
• cheese, grated (about 1/4 cup)

Details

Preparation time 30mins
Cooking time 100mins

Preparation

Step 1

1.Preheat oven to 350°.

2.Place potatoes in a large stockpot; cover with stock. Bring mixture to a boil; cook 4 minutes. Remove from heat. Carefully remove potatoes from pot using a slotted spoon, reserving cooking liquid. Arrange potato slices in a single layer on a jelly-roll pan; set aside. Strain cooking liquid through a fine-mesh sieve over a bowl; reserve 1 cup cooking liquid. Discard solids and remaining cooking liquid.

3. Heat a medium saucepan over medium heat. Add oil to pan. Sprinkle flour over oil; cook 1 minute, stirring constantly with a whisk. Add garlic; cook 2 minutes, stirring frequently. Combine milk and reserved 1 cup cooking liquid. Gradually pour milk mixture into flour mixture in pan, stirring constantly with a whisk. Add thyme sprigs to pan. Bring mixture to a boil; cook 4 minutes or until slightly thick, stirring frequently. Remove from heat. Strain mixture through a fine¬mesh sieve over a bowl, reserving sauce; discard solids. Stir 1/2 teaspoon salt, pepper, and Gruyere cheese into sauce.

4. Spread 1/2 cup sauce in bottom of a broiler-safe 2-quart ceramic baking dish coated with cooking spray. Arrange a single, flat layer of sweet potato and then baking potato slices over sauce. Over flat layer, alternate baking potato and sweet potato slices, in shingle-like fashion. Sprinkle evenly with remaining 1/4 teaspoon salt, 1 tablespoon chives, and chopped thyme; pour remaining sauce over potato mixture. Sprinkle with Parmigiano-Reggiano cheese. Bake at. 350° for 1 hour or until potatoes are tender when pierced with a knife.

5. Remove gratin from oven. Preheat broiler to high.

6. Place gratin in oven. Broil gratin 3 minutes or until browned. Sprinkle with remaining 1 tablespoon chives.
SERVES 8