Kohlrabi Green Tart with Polenta Crust

A recent Good Food Easy CSA installment came with a hefty stack of kohlrabi leaves, an ingredient uncommon enough to render the internet at rather a loss for recipe recommendations. I decided to treat them like greens, but respect their cabbage-ness by pairing them with sweet cooked onions (like this favorite cabbage dish), and to nestle the whole mixture into a tart.

And because we have plenty of polenta from our Lonesome Whistle Farm CSA, I decided to make a polenta crust from this recipe from Maria Speck's Ancient Grains for Modern Meals. The tart crust is basically cooked polenta, with some grated parmesan cheese and an egg for extra integrity. The recipe calls for cooking the polenta in broth, so I made a quick broth with some leek greens and the kohlrabi leaf stems, but I think water would be fine as well. 

I made a couple of mini tarts for the kohlrabi leaf doubters in the house, one of whom opted for a parsley pesto topping while the other went with a take on the classic tomato and cheese pizza. For the rest of us, the kohlrabi green tart was a big hit, and I'm certain I will be making variants with other greens throughout the spring.

Kohlrabi Green Tart with Polenta Crust

Make one 10-inch tart

Crust from Maria Speck's Artichoke Tart with Polenta Crust
1 1/2 cups low-sodium vegetable broth
1 1/4 cups water
1/2 teaspoon sea salt
1 1/4 cups polenta
1/2 cup (about 2.5 ounces) grated Parmesan cheese 
1 large egg, room temperature
1/4 teaspoon freshly ground black pepper

1. Bring the broth and water to a boil in a heavy-bottomed saucepan over medium-high heat. Add the salt. Slowly add the polenta in a thin stream, whisking constantly, and continue whisking for 30 seconds. Decrease the heat to low and cover. Cook for 10 minutes, stirring with a wooden spoon every few minutes to keep the polenta from sticking to the bottom of the pot. Remove the saucepan from the heat and let sit, covered, for 10 minutes, stirring a few times. Stir in the cheese, egg and pepper.

2. Grease a 10-inch tart pan or cake pan with olive oil. Have a glass of cold water ready. Spoon the polenta into the pan and press it out, pushing it up the sides. Dip a wooden spoon or your hands in the cold water to help the polenta along. Set aside for 15 minutes while you preheat the oven to 375 F. Then form an even rim about 3/4 of an inch thick with moist fingers, pressing firmly. Don't worry if the crust looks rustic.

3. Prebake the crust for 20 minutes until it has started to brown on the edges. Meanwhile, prepare the filling

Kohlrabi green filling
6-8 kohlrabi leaves (or substitute collard greens or chard)
1 medium onion
2 tablespoons olive oil
1 cup ricotta (or use Greek yogurt like Maria Speck's original recipe)
2 large eggs
1/2 cup shredded swiss cheese
salt to taste and plenty of freshly ground pepper

1. Cut the center rib from each kohlrabi leaf and cut the leaves into 1 inch ribbons. Peel and dice the onion. Heat a large skillet over medium low heat, then heat the oil and sauté the onions with a pinch of salt, until they are very soft and glassy, about 10 minutes. Add the kohlrabi greens and sauté with another pinch of salt for about 5 minutes until they have turned a darker green and started to soften. Remove from heat.

1. In a large bowl, whisk together the ricotta, eggs, a good pinch of salt and pepper until well-combined. Fold in the sautéed greens. Pour the filling into the prepared polenta tart and spread evenly. Sprinkle with the swiss cheese.

2. Bake the tart until the top turns golden brown and the filling is set, about 40 minutes. Transfer the pan to a wire rack and let cool for at least 20 minutes. The tart can be prepared up to one day ahead.