“Why is this sweet?” a friend of mine asked as he spooned a second helping of cabbage and potato gratin onto his plate.
That’s what happens when you give cabbage a long-enough time in the oven (or in a frying pan): It caramelizes. Like slow-cooked onions, slow-cooked cabbage takes on color, becoming meltingly tender and sweet.
I hadn’t even considered this bonus when I set out to make a cabbage gratin. I was only thinking about how delicious a cabbage gratin that resembled a potato gratin would be. I decided to toss the cabbage with milk and a little crème fraîche, as well as some Gruyère and Parmesan, and to bake the casserole until most of the liquid was absorbed and the top and sides browned (gratinéed).
But cabbage doesn’t have the same kind of power to absorb liquid that potatoes have. Quite the contrary: The cabbage releases water as it cooks. So I threw in some sliced potatoes (one part potatoes, two parts cabbage) so that I wouldn’t end up with a watery casserole.
There was still a little bit of juice that remained in the baking dish after the gratin sat for about 10 minutes, but it didn’t detract from the dish. It is incredibly comforting, with sweet and savory overtones.
And because of the bulk of the potatoes, this gratin makes a satisfying vegetarian main dish, though it certainly works just as well as a side.
Cabbage and potato gratin
Total time: 2 hours; yield: 6 servings
1 large savoy or green cabbage (about 2 pounds), quartered
1 pound baking potatoes, such as russets, peeled and sliced
2 garlic cloves, peeled
2 cups milk
1/2 cup crème fraîche
Ground black pepper
4 ounces Gruyère, grated (1 cup, tightly packed)
1 ounce Parmesan, grated (1/4 cup)
2 teaspoons finely chopped or slivered fresh sage
Bring a large pot of water to a boil, salt generously and add quartered cabbage and potato slices. Reduce heat to medium-high and boil gently for 5 minutes.
Drain and use tongs to transfer cabbage quarters to a colander set over a bowl or in the sink. Allow cabbage to cool in colander until you can handle the wedges. Core the wedges, then cut them in half lengthwise. Finally, slice crosswise into 1/2-inch-wide ribbons. Return to colander and drain for another 5 minutes. Place in a large bowl with the potatoes.
Heat oven to 375 degrees. Butter a 3-quart baking dish or gratin. Cut one of the garlic cloves in half and rub the dish with the cut surface. Then slice up all the garlic and toss with cabbage and potatoes.
In a bowl, whisk together milk, crème fraîche, about 1 teaspoon salt and the pepper. Pour into bowl with cabbage and potatoes, add cheeses and sage and gently toss together. Scrape into baking dish.
Bake 1 hour 15 minutes to 1 hour 30 minutes, until top is golden brown. During the first 45 minutes, press the vegetables down into the liquid in the baking dish every 10 to 15 minutes, using the back of a large spoon. The gratin will still be bubbling when you remove it from the oven, and you will see liquid in the baking dish. Wait 10 to 15 minutes before serving, until liquid is reabsorbed. If liquid remains in dish, serve with a slotted spoon.