Place a baking sheet in the oven and preheat to 400 degrees . Using a blender, mix the milk and eggs for 10 seconds. Blend in the flour and salt for 2 minutes. Let rest.
Meanwhile, in a large cast-iron or other heavy, ovenproof skillet, heat the olive oil over high heat. Place the sausage links in the pan and cook, turning occasionally, until browned and heated through, about 5 minutes. Sprinkle with the scallions, pour the egg batter over the sausages and remove from the heat.
Place the skillet on the baking sheet and bake until puffed and browned, about 45 minutes. Serve hot.
