Heat the oven to Gas 6, 200°C, fan 180°C.
Cut the vegetables into fine (matchstick) strips and place on a sheet of foil. Add 2 slices of lemon and half the butter. Bring the edges of the foil up and seal into a parcel. Place on a baking tray and bake for 20 minutes.
Very lightly grease another sheet of foil with butter. Lay the trout skin-side down on the greased foil. Sprinkle with the almonds and a little grated lemon zest. Dot with the remaining butter. Place alongside the vegetables and cook for 15 minutes until the fish flakes easily.
Undo the vegetable parcel and pile on to a plate with the trout on top.
Serve with steamed new potatoes.