Salmon fillets spread with a mustard-tarragon sauce stay nice and moist when oven baked en papillote, or in parchment. Served with a peppery watercress salad for a fresh pop at the table.
Preheat the oven to 400 degrees F. Fold 2 pieces of parchment paper in half. Then cut a half heart shape, so when it opens it’s a full heart.
Mix the mustard and tarragon in a small bowl.
Put the parchment on a baking sheet and brush with oil. Place the salmon just off center. Sprinkle with a little salt, then spread the mustard-tarragon sauce top of each fillet. Fold the parchment over top and fold the edges to seal. Bake 12 to 15 minutes.
Meanwhile, put the cress in a medium bowl. Drizzle with the oil, lemon juice, a pinch of salt, and toss to coat.
Open the parchment to reveal the salmon. Top with the dressed cress.