01 - Preheat the oven to 400°F and line a baking sheet with parchment paper or lightly grease it.
02 - Pat the salmon fillets dry with paper towels and place them skin-side down on the prepared baking sheet.
03 - Drizzle olive oil over the fillets and season evenly with kosher salt and black pepper.
04 - Place a lemon slice atop each salmon fillet.
05 - Bake for 12 to 15 minutes until the salmon is just cooked through and flakes easily when tested with a fork.
06 - While baking, combine softened butter, chopped dill, lemon zest, minced garlic, and salt in a small bowl, mashing until thoroughly blended.
07 - Remove the salmon from the oven and immediately spread a generous dollop of dill butter on each fillet, allowing it to melt over the hot fish, then serve promptly.