Ingredients

2 tablespoons olive oil
1 lb Swiss or rainbow chard, washed with tough stems removed
1 Vidalia onion, medium dice
1/4 cup chicken broth or water
2 cups whole milk
1/2 cup heavy cream
3/4 cups polenta (corn grits)
1 bunch of chives, minced
2 teaspoons fresh thyme leaves, minced
Salt and freshly ground pepper
1/2 cup Cabot or other cheddar cheese
3 large eggs, separated
1/2 cup grated Parmesan cheese

Method

Place rack in middle of oven and preheat to 350°. Butter or oil a 9x13" baking dish.

Stack and roll up 5 or 6 chard leaves like a cigar. Slice across the rolls into thin ribbons. After slicing all the greens, heat a large frying pan on med-high heat and add the olive oil. Add the onion and the chard and cook until the greens are wilted. Add the water or chicken broth, cover and reduce heat to low. Cook, stirring occasionally, until greens are tender and the liquid is absorbed, about 20 minutes. Put greens in a colander to drain any remaining liquid. Transfer to a large bowl.

While chard is cooking, bring milk and cream to a simmer in a heavy saucepan. Add polenta, whisking to prevent lumps. Add the chives, thyme, salt and pepper. Cover and cook over low heat, stirring frequently, until the polenta is tender and the liquid is absorbed, about 20 minutes. If the polenta gets too thick before it is tender, add more milk and reduce the heat. Remove from heat and stir in the cheddar cheese. Add to the bowl with the greens and stir to combine. 

Lightly beat the eggs yolks and stir into the polenta mixture. Put eggs whites into a large bowl and beat with an electric mixture until stiff peaks form. Use a spatula to carefully fold the egg whites into the warm polenta mixture. Pour into the prepared pan. Sprinkle with Parmesan cheese. Bake for about 40 minutes, or until top is golden brown. Serve hot.

This recipe can be prepared the night before baking. Cover and refrigerate the assembled casserole overnight. Remove from refrigerator one hour before baking. Bake in preheated 350° oven until golden on top.