Au gratin potatoes are a family-revered dish of decadence. A common au gratin preparation uses potatoes, but, really, you can use any combination of vegetables. Traditionally, layers of potato and onion come smothered in a buttery cream sauce and melted cheese. No matter how you cut the potato, au gratin potatoes are rich, starchy and leave diners feeling heavy and overindulgent—almost.
Though sometimes described as bitter, turnips are an ideal substitute for potatoes. Turnip root is significantly lower in carbohydrates and is a wonderful option for a low-glycemic diet. Typical southern preparation of turnips uses a ham hock or salted pork for seasoning. Turnip greens and the diced root are stewed together until tender and bitterness reduced. Southern-style turnips are delicious, but what is a healthier alternative for cooking with turnips?
The answer lies in the least likely of preparations—au gratin. Thin layers of tender, not bitter, turnip root, savory sautéed spinach and caramelized sweet onion meld together in a light yet filling casserole worthy of serving for brunch or at at a spring tea.
As always, adjust recipe to dietary needs and personal tastes.
6-8 medium turnip roots
2 large sweet onions (Vidalia or Walla Walla)
3 pounds frozen spinach
2 tablespoons minced garlic
1 teaspoon crushed red pepper flakes
1 teaspoon ground nutmeg
1/3 to 1/2 cup walnuts
6 wheat crackers
1 cup grated Gouda cheese
6 to 8 slices American cheese
1 tablespoon dried thyme
3 tablespoons olive oil
3 to 4 tablespoons unsalted butter (cut into cubes)
1 to 2 cups 2-percent milk (enough milk to fill bottom third of casserole dish)
Salt and pepper
Non-stick cooking spray
Bring a pot of well-salted water to boil. Peel, halve lengthwise, and cut turnip roots into 1/4-inch slices. Blanche sliced turnips in boiling water for no more than five minutes.
Remove turnips from boiling water and submerge into ice water bathe. When completely cooled, drain turnips and set aside until ready to use.
Peel away the outer layer of onion and cut the rest into 1/4-inch slices. Spray skillet with non-stick cooking spray. Sauté onion until softened and slightly caramelized. Remove onions from heat and set aside.
Thaw, drain and squeeze excess moisture from spinach. Sauté spinach with garlic, red-pepper flakes and nutmeg until combined. Remove spinach from heat and set aside.
In food processor, pulse walnuts and crackers until well crumbled. Combine crumbles, grated Gouda, thyme and olive oil until well combined and set aside for casserole assembly.
Spray bottom and sides of oblong or rectangular casserole dish with non-stick cooking spray. Begin layering slices of turnip vertically against the short side of dish. Against the turnip layer, lay some of the sautéed onion and then a layer of sautéed spinach. Layer another wall of turnip, and gently press the first layers closer together.
Continue layering and sandwiching to the other side of the dish. Layer remaining ingredients on top.
Add enough milk to fill the bottom third of casserole dish. Season top of casserole with salt and pepper to taste. Cube butter and spread cubes evenly across top of layers. Cover bottom layers with slices of American cheese and finish with Gouda-walnut topping.
Bake at 350 degrees until bubbly and the topping is browned.
Serves six to eight guests.