1lbgreen cabbagecore and tough inner leaves removed. Diced ½ inch
½cupshallotdiced ¼ inch
½teaspoonkosher saltor more to taste
Fresh ground black pepperto taste
2tablespoonunsalted butterplus 2 tablespoon for finishing the gratin
½cupshredded gruyere cheese
1teaspoonchopped fresh thyme
1/2cupchicken stockpreferably homemade
½cuptoasted breadcrumbslike panko, or sourdough
1tablespoonchopped Italian parsley
Sweat the shallot in 1 tablespoon of the butter for 2 minutes, then add the cabbage, 1/4 cup of the chicken stock and season to taste lightly with salt and pepper, cook until the cabbage is wilted and tender, about 10-15 minutes on medium-low heat, stirring occasionally. Try not to have the cabbage brown, if the pan gets dry, add a little of the chicken stock. Drain the cabbage of excess liquid in a collander, you should end up with about 2 cups of packed, tender cabbage. Reserve.
Wilt the cauliflower mushrooms and brown very lightly in the other tablespoon of butter, seasoning with salt and pepper to taste. Cool the mushrooms, then mix with the cooked, cooled cabbage, thyme and gruyere.
Preheat an oven to 350 degrees. Pack the mushroom-cabbage mixture In a wide gratin dish or casserole and drizzle the remaining chicken stock over it. Mix the breadcrumbs with the parsley, sprinkle over the top, then dot the whole mixture with the remaining 2 tablespoons of butter. Bake for 15 minutes or until hot throughout and browned, then serve. The gratin can be assembled ahead of time, then brought to room temperature before baking.