Flake crab meat in a bowl and make sure there are no shell pieces; set aside.
In a skillet, saute mushrooms and green onion in the 1-1/2 Tablespoons butter. Add crab and heat through.
In a small cup, stir together cornstarch and water; add to crab mixture. Add cream, wine, and lemon juice.
Cook, stirring constantly, until thickened and smooth. Blend in seasonings; taste and adjust if necessary.
Divide among desired size containers.
Combine bread crumbs, Parmesan, and melted butter; sprinkle over crab. Place under preheated broiler for about 3 or 4 minutes or until lightly browned and crispy. Serve with crusty bread or crackers. Serves 4 as an appetizer.
Recipe by The Culinary Cellar at https://theculinarycellar.com/crab-au-gratin/