Preheat oven (electric cooker: 200 °C/circulating air: 180 °C/gas: see manufacturer). Wash and dice tomatoes. Clean, wash and chop spring onions. Peel or clean carrots and zucchini, wash and grate them coarsely.
Rinse the fish, pat dry, place on 4 large pieces of aluminium foil or parchment paper. Season with pepper. Spread vegetables over it. Fold the foil into packages. Bake in a hot oven for about 15 minutes.
Squeeze lime. Mix with soy sauce, honey and 1 tsp. five-spice powder. Wash the coriander and remove the leaves. When cooked, remove the fish and vegetables from the packet and add the marinade and coriander.