We spend the summer crunching on raw kohlrabi, making fresh salads, tossing it into stir-fries, but another way to enjoy kohlrabi is creamy like this gratin. My first instinct with kohlrabi was to roast it, but it’s honestly not the best roasting vegetable. The best preparations are lightly cooked or simmered in a liquid like soup. If you want something rich and comforting, try this gratin – a traditional potato dish with layers of thinly sliced kohlrabi.
This gratin recipe has a shortcut that’s genius. The vegetables are simmered in half and half on the stove before baking. The half and half thickens from the starch and you get the chance to taste it before baking. I’ve made disappointing gratins in the past, dishes where the potatoes never really cooked, or the salt and pepper wasn’t strong enough. Using this method it’s perfect every time. I’d serve it with grilled fish or if you want to get decadent a grilled steak. For vegetarians this is hearty enough to just add a salad.
Take your time to cut the potatoes and kohlrabi into thin even slices. If you have a mandoline you can use that, but it really doesn’t take much time to peel and slice by hand. If you have a low wide dish that can go from oven to stove top use it. It makes this an easy one pot dish. Otherwise just transfer the mix to a shallow baking pan before topping it with flavorful grated gruyere.
Potato Kohlrabi Gratin
2 lbs potatoes, peeled and thinly sliced
1 kohlrabi, tough skin removed, quartered, and thinly sliced
2 – 3 cups half and half
4 tablespoons butter, chopped into small pieces
1 garlic clove smashed
1 cup grated gruyere cheese salt and pepper
Preheat the oven to 400°F Place the potatoes, kohlrabi, garlic, butter, and 2 cups of the half and half in a sauté pan. Layer the potatoes and kohlrabi so the vegetables are evenly mixed. Add more half and half if necessary, to just barely cover the vegetables. Bring to a boil, cook for 6 – 8 minutes. The potatoes should be tender, but not all the way cooked, you don’t want them to fall apart. The half and half will be thickened from the potato starch. Taste and adjust with salt and pepper if necessary.
Spread the cheese over the vegetables and bake for 20 – 30 minutes until the vegetables are cooked and the cheese is golden brown. Let sit 10 minutes before serving.
*If necessary transfer to a shallow baking dish or 8×8 pan.