Rinse fish thoroughly; pat dry, and set aside.
Combine flour, 1/4 cup butter, and half-and-half, mixing well. Set aside.
Combine breadcrumbs, tomato, onion, cucumber, celery, 3 tablespoons melted butter, and chopped celery leaves in a large mixing bowl; stir mixture well. Sprinkle fish cavity evenly with salt and pepper, and place stuffing in cavity. Close opening with wooden picks, and tie with string.
Place prepared fish in a large shallow roasting pan, and spread flour mixture evenly over top. Pour 1 1/2 cups milk around fish. Bake, uncovered, at 400° for 45 minutes or until fish flakes easily when tested with a fork, basting occasionally with pan drippings.
Transfer fish to a warm serving platter. Serve immediately.
Oxmoor House Homestyle Recipes