Preheat the oven to 425˚F.
Tear off a large piece of parchment and lay it on a rimmed baking sheet.
Lay the fish filet on the parchment, sprinkle with herbs and top with the lemon slices, then drizzle with oil and sprinkle with salt.
Fold the parchment over the fish and fold the edge to seal it closed.
Bake for 15 minutes, or until the fish is firm to the touch.
Carefully open the package (it will be steamy)—the edge of the fish should flake with a fork, but the middle should still be moist.