Preheat the oven to 300 degrees.

Cut 8 pieces of parchment paper (or aluminum foil) into squares large enough to cover each fish fillet and leave a 2-inch border all around. Lightly brush 4 squares of the paper with oil.

In the center of an oiled square, layer a quarter of the spinach, 1 tablespoon of the crème fraîche, 2 fillets, 1 teaspoon of the shallots and 2 slices of lime. Season with salt and pepper to taste.

Place the remaining parchment squares on top of the fillets and fold up the edges to form packets. Simply double folding each of the four sides is enough to seal each packet. Put the papillotes on a baking sheet, and bake in the preheated oven for 15 to 20 minutes.

Serve at once by setting each papillote on a plate.


Note: You can use sole or snapper instead of red mullet.