Meanwhile, prepare an ice-water bath; set aside. Bring a medium pot of water to a boil; blanch asparagus and scallions until bright green, about 1 minute. Immediately transfer with a slotted spoon to ice-water bath to stop the cooking. Drain; set aside.

Heat oil over medium heat in a large skillet until hot but not smoking. Add onions; cook, stirring occasionally, until just tender, 2 to 3 minutes. Stir in carrots and radishes; cook 1 minute. Stir in mushrooms, ginger, garlic, and butter. Add wine and stock; cook until liquid is reduced by half, about 5 minutes. Remove from heat. Stir in reserved asparagus and scallions; season with salt and pepper.

Spoon 1/2 cup vegetable mixture into each of six 5-ounce ramekins. Lightly beat egg and cream in a small bowl; brush egg wash around rims of ramekins.

Roll out puff-pastry rounds to 4 inches in diameter. Lightly press a pastry round over each ramekin. Brush tops with egg wash. Place a puff-pastry flower on each pot pie; lightly brush with egg wash.