Sweet Potato, Turnip, and Celeriac Gratin

February 02, 2022

It's hard knowing what to do with winter's root vegetables. However many ways we seem to prepare them, root veggies can feel, at times, not all that versatile. But that's where we home cooks are sorely mistaken! Classic preparations for winter produce may be tried and true, but we're in desperate need of something refreshing to do with this year's abundant harvest of earthy vegetables. Something doable on weeknights! Something addictively tasty!

Introducing: the winter gratin. In what's essentially an ooey-gooey amalgam of root veggies and cave-aged cheese, bolstered by a few umami-forward helpers like the ever-popular Yondu Umami Sauce. This recipe is extremely forgiving of substitutions (everything tastes good when it's smothered in cheese!) and we encourage you to make this dish your own by riffing on the original recipe with whatever you've got on hand. This is a great opportunity to alleviate your fridge of any left-behind morsels of herbs or greens, plus it'll result in a seemingly never-been-done-before meal each and every time you make it!


Serves 4



2 Tbsps. quality olive oil

4 Tbsps. Local Roots unsalted butter

2 Local Roots yellow onions, diced or sliced into thin half-moon shapes

3 cloves garlic, finely chopped

1 cup Local Roots shiitake mushrooms, thinly sliced

2 sprigs fresh thyme, finely chopped

1 Local Roots sweet potatopeeled and cut into ½-inch batons

1.5 lbs. Local Roots Scarlet Queen turnips (another variety will do), peeled and cut into ½-inch batons

1 Local Roots celeriac, peeled and cut into ½-inch batons

2 Tbsps. Local Roots all-purpose flour

2 Tbsps. Yondu Umami Sauce (substitute with either white miso paste or a slurry of soy sauce and tahini)

½ cup dry white wine (optional, helps with deglazing, substitute with more broth)

2 cups Local Roots chicken broth

½ cups Local Roots cave-aged cheddar cheese, coarsely grated

Salt and freshly ground pepper to taste 



1. Heat oven to 375 degrees. In the meantime, heat a cast iron skillet over medium heat. Once heated, add oil and butter. Once melted, add onion and a pinch of salt and cook, stirring occasionally, until translucent and slightly darkened in color. 

2. Add garlic, mushrooms, and thyme and cook for three minutes until aromatic. Add Umami sauce (sub with miso paste/soy sauce and tahini slurry) and white wine if using. Cook, stirring, for five minutes, until alcohol has evaporated and liquid has reduced by about half. Remove from heat.

3. In a large bowl, toss root vegetables in flour and season generously with salt and pepper. Pour onion mixture into the bowl and toss gently, taking care not to break the batons. 

4. Return mixture to the cast iron and add chicken broth. Cover gratin with a greased sheet of tin foil and bake for about one hour or until vegetables are tender. 

5. Once cooked through, remove from oven and set oven to 450 degrees. Top evenly with cheddar cheese and return to oven, uncovered, for another 30 minutes or until cheese is browned and crisp.

6. Remove from oven and let rest 20 minutes before serving.


This recipe was created by Local Roots recipe contributor Jess Santoro // @jess_santoro

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