I have a secret love for kohlrabi. Kohlrabi has a wonderful, sweet flavor somewhere between turnip and broccoli. But you so rarely see it for sale anywhere that we mostly just dream about it. That's why we planted it in the garden this year--to satisfy our craving for kohlrabi anytime we like.
Our friend Larry calls kohlrabi "a little sputnik" because of its globe shape sprouting long leaf stems. It's not a root vegetable, but a swollen stem. Until recently, it never occurred to me that the leaves might be edible. That's something we'll have to try. Meanwhile, I usually prepare kohlrabi as simply as possible, just cutting it into large matchsticks, cooking it in salted water and tossing it with melted butter. But I wanted to do something that would really make kohlrabi shine. I thought it would be a perfect candidate for a gratin.
I make a delicious rutabaga gratin, and a dynamite sweet potato gratin stuffed with wilted greens. A classic potato gratin has fans who are very particular about the way it is cooked in the oven. So I consulted Madeleine Kamman--who is just about the most finicky cookbook author I know, and a damned good instructor--to see what she had to say about the classic gratin method.
There's nothing particularly difficult about the method Kamman describes. In fact, it could hardly be simpler: use lots of heavy cream and let is bake a long time. As the cream browns, scrape it from around the edges of the casserole and push it from the surface under the cream underneath. Continue doing this until there is hardly any cream left, and what cream there is is studded with brown bits.
For a kohlrabi gratin:
1 clove garlic, crushed
1 tablespoon butter
1 lb kohlrabi, trimmed and peeled (I used a serrated knife to remove the peel)
1 1/2 cups heavy cream
2/3 cup grated cheese (combine Parmesan with Emmentaler)
Preheat oven to 325 degrees
Rub the inside of a small, shallow ceramic casserole with the garlic. Grease it with the butter. Meanwhile, slice the kohlrabi very thinly. You may want to first cut it in half from end to end. Lay the kohlrabi slices in the casserole overlapping like shingles, seasoning them with salt as you go. You may make two or three layers. Cover with the cream and shake the casserole a little to distribute the salt.
Lay the casserole on a baking sheet and place in the oven. As the cream browns, break it up and push it under the cream underneath, scraping any brown bits from the side of the casserole and incorporating those as well. Continue doing this for about 1 1/2 hours, or until the kohlrabi is perfectly tender and the cream has been almost completely absorbed. Sprinkle the cheese over the gratin and continue baking until the cheese is completely melted and lightly browned. Serve hot.
We had this last night with a wonderful salad of fresh tomatoes from the garden with fresh mozzarella cheese and basil. This is not something we would eat on a daily basis. But for now, my craving for kohlrabi is completely and utterly indulged.