I found a version of this recipe in Bon Appetite magazine using asparagus. I had some bok choy I needed to use up soon, so I simply switched the ingredients. Feel free to do the same with what you might have hanging around in the fridge. If you're using asparagus I would steam them first and transfer them to a bowl of ice water to let cool.
I've made a few different versions of this recipe. It's nice and easy. Most of the time I'll add spinach, garlic, ginger, sesame oil, red pepper and lime juice for an Asian flavour. It's great served over top some fluffy rice to soak up all the juices.
1 garlic cloves, minced
1/2 Tsp of salt
2 Tbs of butter
1 Tbs of olive oil
1/3 cup fresh lemon juice
1 1/2 Tsp grated lemon peel
1/2 Tsp ground black pepper
2 Cod fillets, pinbones removed
4 Paper-thin prosciutto slices, halved lengthwise
For the fish:
Mash garlic and salt to paste in small bowl. Melt butter with 1 tablespoon of oil in small nonstick skillet over medium heat. Add garlic paste; stir until pale golden, about 1 minute. Stir in lemon juice, peel, and black pepper. Remove from heat.
Preheat oven to 500F. Cut out 2 squares of parchment paper large enough to hold the fish. Place 1 parchment square on work surface. Drizzle 1 teaspoon oil over parchment. Place 1 cod fillet in centre of parchment. Spoon half of the garlic-lemon mixture over fish. Cover with half of the bok choy spears. Arrange 2 slices of prosciutto over top. Fold 2 opposite sides of parchment in over fish and vegetables, then fold in remaining 2 sides, enclosing completely. Fasten parchment edges together with toothpicks to seal packet. Place on large rimmed baking sheet. Repeat procedure with remaining parchment, oil, fish, garlic-lemon mixture, bok choy, and prosciutto. Bake fish until just opaque in center (parchment will turn golden brown), about 12 minutes. Transfer 1 parchment packet to individual plate. Open parchment packets and serve. You can be prepare 6 hours ahead and refrigerate.