Cooking fish en papillote means you'll be cooking it in a parchment pouch. When you seal the fish in this manner, it will cook from the steam generated inside the "package" and maintain its moisture, meaning you don't have to use a lot of butter or oil.
2 X 115 g/ 4 oz. fillets of any white fish (sole, tilapia, haddock)
2 tsp olive oil
1 teaspoon capers
1 clove garlic, thinly sliced
2 stems fresh thyme
8 cherry tomatoes
2 slices lemon
salt and pepper
2 large squares parchment, about 30 cm each side
Preheat oven to 400 °F.
Lay one fillet just a bit lower than halfway down the parchment square and season with salt and pepper.
Pile half of the capers, garlic, thyme and cherry tomatoes on (or around) the fish. Drizzle with lemon and 1 tsp olive oil and put the lemon itself on top.
Fold the parchment over the fish so the parchment edges touch. Now seal the edges making small continuous folds until you have a crescent shaped package, tightly sealed.
You can use the back of a knife to really make a sharp crease to ensure the package is closed at both ends.
Repeat with the other fillet.
Put the packages on a baking sheet and into the oven. Bake until the fish is cooked through — about 8 to 10 minutes.
Remember to be careful when opening the packages as they can release hot steam.
Feel free to change up the herbs, veggies or seasonings to suit your tastes. You can substitute white wine for the lemon.