Preparation Preheat oven to 400°F with a baking sheet on bottom rack. Cut potatoes into very thin slices with slicer. Toss potatoes with 2 tablespoons oil, 1 teaspoon oregano, and 1/4 teaspoon sea salt. Divide potatoes among parchment squares, arranging them in center, slightly overlapping, then top with a piece of fish. Sprinkle each fillet with a scant 1/4 teaspoon sea salt, then top each with a lemon slice, a few garlic slices and olive slivers, parsley leaves, 1/2 teaspoon oregano, and 1/2 tablespoon oil. Gather sides of parchment up over fish to form a pouch, leaving no openings, and tie tightly with kitchen string. Put packages on hot baking sheet and bake until fish is just cooked through, 15 to 22 minutes. Cooks' note:Fish can be assembled in parchment 4 hours ahead and chilled.
Preparation Preheat oven to 400°F with a baking sheet on bottom rack. Cut potatoes into very thin slices with slicer. Toss potatoes with 2 tablespoons oil, 1 teaspoon oregano, and 1/4 teaspoon sea salt. Divide potatoes among parchment squares, arranging them in center, slightly overlapping, then top with a piece of fish. Sprinkle each fillet with a scant 1/4 teaspoon sea salt, then top each with a lemon slice, a few garlic slices and olive slivers, parsley leaves, 1/2 teaspoon oregano, and 1/2 tablespoon oil. Gather sides of parchment up over fish to form a pouch, leaving no openings, and tie tightly with kitchen string. Put packages on hot baking sheet and bake until fish is just cooked through, 15 to 22 minutes. Cooks' note:Fish can be assembled in parchment 4 hours ahead and chilled.