1 Baking sheet, 1 Bowl, 1 Small bowl, 1 Cutting board, 1 Large knife, 1 Small knife, 1 Tablespoon, 1 Peeler, 1 Kitchen twine, 1 Parchment paper
1 Trim both ends of lemongrass, peel tough outer layer and cut stalk in half lengthwise. Mix curry powder with oil. Squeeze juice from lime. Mix 1 tablespoon juice into the curry and reserve remaining juice. Season oil with salt and pepper.
2 Rinse the trout inside and out in cold water and pat dry. Tuck 2 lemongrass halves in each abdominal cavity. Rub the trout inside and out with curry oil.
3 Cut banana leaves into 4 pieces, about 50 x 25 cm (approximately 20 x 10 inches), rinse and pat dry.
4 Place fish on the bright side of banana leaves.
5 Wrap fish in banana leaf, place seam side up and tie into a bundle with kitchen twine. Place bundles on a baking sheet lined with parchment paper and sprinkle with a little water. Bake on lowest rack of preheated oven at 200°C (fan: 180°C, gas: mark 3) (approximately 400°F) for 25-30 minutes.
6 Meanwhile, peel cucumber, halve lengthwise, remove seeds and cut flesh into 1 cm (approximately 1/2-inch) cubes.
7 Peel melon, remove seeds and cut into 1 cm (approximately 1/2-inch) cubes.
8 Combine yogurt and reserved lime juice with cucumber and melon in a bowl. Season with salt and pepper.
9 Rinse mint, shake dry, pluck leaves and chop finely. Mix with the yogurt mixture.
10 Remove fish bundles from the oven, remove the twine and open banana leaves. Pull on the dorsal fin: If it removes easily, the fish is finished cooking. Otherwise, return to oven and cook for a couple more minutes. Serve fish with the cucumber and melon yogurt.