- 1 tablespoon butter, plus extra for dish
- 2 shallots, sliced
- 3 cloves garlic, minced
- 1 pound bulk Italian sausage
- 3 pounds braising greens (kale, mustard, chard, collard, etc.), tough stems removed and leaves, cut into small pieces
- 1/8 teaspoon freshly grated nutmeg
- Salt and pepper, to taste
- 1/2 cup chicken stock
- 1 cup heavy cream
- 1 cup grated Gruyere cheese
Preheat oven to 375° F. Butter an 8-inch square baking dish.
Melt butter in a large skillet over medium heat. Add shallots and garlic and cook until soft, about 10 minutes. Stir in sausage and cook, breaking into small pieces, until cooked through, about 10 minutes. Drain off fat, if desired.
Add braising greens, in batches, stirring until cooked down. When all greens have been added, cook and stir for 5 minutes; season with nutmeg, salt and pepper. Add chicken stock and cook 5 additional minutes. Transfer greens to the prepared dish. Drizzle with cream and sprinkle with cheese.
Bake until cream is bubbling and cheese is golden, 20 to 30 minutes. Serve warm or at room temperature.
Make ahead: Cook and cool gratin; cover with foil and refrigerate overnight. Bring to room temperature and reheat in a 350° F oven for 10 to 20 minutes.