Spread the foil and put the asparagus on it, in General, asparagus can be replaced with any frozen vegetables (beans, broccoli, etc.).
Season with salt and pepper, sprinkle with rosemary, cut three slices from half a lemon and put on the fish, and squeeze the juice from the rest of the lemon on the fish.
Close the foil, but do not wrap it too tightly. Put in a preheated 180-200 degree oven.
After 20 minutes, you can remove it. The sauce is absolutely any, I often do just Bechamel, my husband sometimes asks for cream mushroom - in General, everything is optional)))