Preheat the oven to 400°F.
Salt the cabbage: In a colander, salt the cabbage all over with about 2 teaspoons of kosher salt and set aside for 5 minutes.
Make the topping: Meanwhile, in a small bowl, combine the melted butter, panko breadcrumbs, and grated Parmesan. Set aside.
Brown the cabbage: Heat the olive oil in a 12-inch skillet over medium-high heat. Blot the chunks of cabbage with a paper towel and place in the pan, cut side down. Sear on both sides until some golden brown color begins to appear, about 5 minutes total. Turn off the heat.
Make the sauce: When all of the cabbage pieces have been seared, nestle them together in the pan and cover with the heavy cream, minced garlic, 1 teaspoon kosher salt (or to taste), black pepper, and shredded gruyere. Use a wooden spoon to gently stir the mixture.
Add the topping and bake: Top with the Parmesan panko breadcrumbs and bake until the cheese melts and the cream thickens, about 40 minutes. Allow to cool for 15 minutes before serving. Refrigerate leftovers for up to 5 days. For best results, reheat in a pan on the stove over medium heat. Love the recipe? Leave us stars and a comment below!
