Step 1

Heat the oven to 400°F. Line a rimmed baking sheet with aluminum foil.

Step 2

Pat 4 (6-ounce) salmon fillets dry with paper towels and place on the baking sheet. Brush all over, including the bottoms, with 1 tablespoon of the olive oil, then season with 1/2 teaspoon of the kosher salt and 1/4 teaspoon of the black pepper. Arrange skin-side down.

Step 3

Roast until the salmon is opaque and flakes easily with a fork, 12 to 15 minutes. An instant-read thermometer inserted into the middle of the thickest part should register 120°F to 130°F for medium-rare, or 135°F to 145°F for well-done.

Step 4

Meanwhile, thinly slice 3 medium scallions, keeping the dark green parts separate from the white and light green parts. Heat the remaining 1 tablespoon olive oil in a small skillet over medium heat until shimmering. Add 1/2 small diced fennel bulb and the white and light green parts of the scallions. Cook until softened but not browned, about 4 minutes.

Step 5

Remove the skillet from the heat. Stir in 2 ounces room-temperature cream cheese and 2 tablespoons water until smooth. Stir in the dark green scallions parts, 1/4 cup finely chopped fresh parsley leaves, 1 tablespoon finely chopped fennel fronds, and the remaining 1/4 teaspoon kosher salt and 1/4 teaspoon black pepper. Taste and season with more kosher salt and black pepper as needed.

Step 6

Remove the salmon from the oven and turn the oven to broil. Divide the cream cheese mixture between the salmon fillets (about 2 tablespoons each) and spread evenly over the top of each fillet. Broil until the topping is browned in spots, about 3 minutes. Serve with lemon wedges.