In a 2-quart glass dish, combine hash browns, and onions. Cover and microwave on high for six minutes, or until onions are tender, stirring once during cooking time. In a mixing bowl, combine egg whites, milk, salt, and black pepper. Mix well. Pour over hash browns. Cover and microwave on high for four minutes, or until just about set, stirring once during cooking time. Arrange links in center of each tortilla. Spoon 1/3 cup egg white mixture over links. Roll up with filling inside. Place seam-side-down in a glass dish. Cover and microwave on high for three and half minutes, rotating dish once during cooking time. Let stand three minutes before serving. Spoon a little picante sauce over each tortilla just before serving.