Salmon with Fennel Baked in Parchment

fennel bulb, sliced paper thin (a mandoline helps for this)

portions of fresh salmon fillets (skinless is best)

Kosher salt

Freshly ground black pepper

Lemon juice (to taste)

very thin slices of whole lemon (from 1 to 2 lemons)

Several sprigs of fresh fennel fronds

butter

12x18-inch pieces of parchment paper (can sub aluminum foil if you don't have parchment paper)