How do I store leftovers?

Leftover parsnip, potato, and leek gratin can be stored it in an airtight container in the refrigerator for up to 4 days.

What is a thin-skinned potato?

Potatoes can be divided into two main categories, waxy and floury. Waxy potatoes are thin-skinned varieties that include White, Chef, Red Bliss, and Yukon Gold. These potatoes are typified by their thin, smooth skin, creamy texture. Thin-skinned potatoes lend themselves nicely to moist heat cooking methods, such as simmering in soups and stews, boiling, steaming, or mashing for mashed potatoes. The second category, Russet or Idaho, falls into the floury category. These potatoes have rough, thicker skin, and a light/fluffy/starchy interior, that is perfect for baking, roasting, or other dry-heat cooking methods.

I don't like the flavor of parsnips; can I substitute another vegetable?

Parsnips have a unique flavor. This winter root vegetable tends to have subtle sweetness that can be laced with undertones of bitterness. For some palettes, this flavor profile is undesirable so feel free to swap out the following for parsnips: turnips, rutabaga, celery root, or even sweet potato. Or simply skip them and use more potatoes!

The Best Parsnip, Potato, and Leek Gratin

Description

Light scalloped potato or potato gratin recipe with parsnips, leeks and extra sharp cheddar. This is a wonderful make-ahead dish, making it the perfect side to any weeknight meal or holiday celebration.

Ingredients

Units Scale

2 1/4 cup low-fat milk, divided
2 cloves garlic, crushed and peeled
1/3 cup all-purpose flour
1 tablespoon Dijon mustard
1 teaspoon salt
1/4 teaspoon ground pepper, preferably white
pinch nutmeg
6 ounces shredded extra-sharp cheddar cheese, divided (1 1/2 cups)
2 ounces shredded Parmesan cheese (1/2 cup)
3 pounds thin-skinned potatoes
1 pound parsnips, peeled (about 2 medium)
2 medium leeks, thinly sliced and washed
2 slices bread, preferably sour-dough or mild whole wheat, crusts removed if desired
2 teaspoons extra-virgin olive oil
1/2 teaspoon paprika
1/4 teaspoon garlic powder
2 tablespoons freshly chopped parsley

Cook Mode Prevent your screen from going dark

Instructions

Preheat oven to 350 degrees F. Coat a 9 by 13 baking dish (or similar size) with cooking spray.
Heat 1 ½ cup milk and garlic in a large saucepan over medium-high heat until steaming. Whisk the remaining ¾ cup milk, flour, mustard, salt, pepper and nutmeg in a medium bowl until smooth. Whisk the flour mixture into the hot milk and continue cooking, stirring often until mixture bubbles and thickens, about 7 minutes. Remove from the heat and remove garlic cloves with a slotted spoon. Stir in 4 ounces (1 cup) cheddar and Parmesan. Whisk until smooth.
Slice potatoes and parsnips into 1/8-inch slices using a mandolin or sharp knife.
Spread 3 tablespoons of the cheese sauce into the bottom of the prepared dish. Layer in one third of potatoes, parsnips and leeks. Pour about one third of cheese sauce over the vegetables. Repeat with a two more layers of vegetables and cheese sauce.
Cover with a layer of parchment and then foil, and bake until the vegetables are tender, 1 hour 40 minutes.
Tear bread into pieces and process in a food processor until it becomes fine crumbs. Add oil, paprika and garlic powder and process until evenly moist and orange.
Remove foil from the gratin. Sprinkle the remaining 2 ounces (1/2 cup) cheddar over the top. Spread the bread crumb mixture over the top. Return to the oven and continue baking until golden brown, about 20 minutes longer. Let cool fifteen minutes before serving topped with parsley.

Notes

Serving Size

The serving size here is really generous, so if you’re serving several side dishes, this will serve more like 15 or 16 people!

Make Ahead

To make ahead, prepare assemble casserole per recipe card up to step 4. Do not bake per step 4, instead cover with foil and place in the refrigerator. When ready to serve, continue with the last two remaining steps on the recipe card, keeping in mind that the dish may need any extra 10 to 15 minutes to warm all the way through in step 4.

Prep Time: 25 minutes
Cook Time: 2 hours
Category: Side Dish
Method: Oven
Cuisine: American

Nutrition

Serving Size: 1/12th casserole
Calories: 224
Sodium: 414
Fat: 6 grams
Saturated Fat: 4 grams
Fiber: 3 grams
Protein: 11 grams