Preheat oven to 400 degrees.
Butter a shallow 2 quart baking dish (8-by-11-inch). Melt 2 tablespoons butter in a sauté pan or large frying pan over medium high heat and add cabbage wedges cut side down. Sprinkle with ¾ teaspoon salt and ½ teaspoon pepper; cook, turning once, until lightly browned, 5 to 7 minutes.
Add ¼ cup water to pan. Partially cover and cook cabbage until tender, 3 to 5 minutes more. Transfer cabbage to prepared dish, arranging wedges flat but snug.
Return pan to medium heat, melting remaining butter. Add garlic, chopped thyme, nutmeg, flour and stir. Add cream and stir until bubbling, about 2 minutes.
Pour cream mixture over cabbage. Top with cheese and bread crumbs. Bake until browned and bubbling, about 20 minutes. Garnish with thyme sprigs and season to taste with salt and pepper.