For the marinade, mix salt, pepper, chopped parsley, olive oil and a little lemon juice in a bowl.
Peel, halve and slice the sweet potato and beetroot.
Line a baking sheet with parchment paper and layer the sweet potatoes and beetroot so that it makes a nice bed for the trout. Pour 100 ml of water over it. Salt and pepper the bed.
Wash the trout and pat dry with kitchen paper. Now rub the trout with the prepared marinade inside and out. Place the trout on the bed of vegetables, put lemon wedges on top.
Bake in a preheated oven at 220 ° C top / bottom heat for 30 minutes.