It's really just fish in parchment paper...but en papillote just sounds so sweet :)
We just taught a great cooking class on healthy and delicious food and a couple of days before that we thought we should really retest the temperature for making a couple of thick fish fillets. Our test recipe came out very delicious and satisfying, so it's more than worth sharing.
Mahi mahi in parchment paper
two large mahi mahi fillets (use any meaty thick fish)
1/2 bell pepper
1 zucchini squash
1 tbsp butter
2 tbsp olive tepanade (or chopped up olives)
lemon pepper to taste
Preheat the oven to 400 F (200C). Prepare the vegetables, by cutting them in long strips or large slices (for the pepper). Proceed to cut a large piece of parchment paper and lay the vegetables tightly in a row. Place the fish on top and season with the lemon pepper. If you don't have lemon pepper, just sprinkle salt, pepper and some lemon zest or place whole slices of lemon. Place olives and butter on top.
Bring the ends of the paper together at the top, roll tightly in and fold under. You can staple it to make sure no moisture escapes. Roll in from the ends and staple again. The goal, no matter how you fasten the paper, is to let no moisture escape, as the steam is what cooks the fish and vegetables.
Place in the oven for 20 minutes. If your fish fillets are smaller, feel free to cook less - 10-12 minutes.
Serve by cutting the tops off the paper packages with scissors and letting some of the moisture and heat escape, then placing on a warm plate.
This recipe can use about any type of fish, vegetable or spice you can think of. If you want to try something very simple, use olive oil, lemon, salt and some cherry tomatoes when you next cook salmon. Just don't forget to do it en papillote!