Take the salmon out of the fridge and let it sit at room temperature for about 10 minutes. Meanwhile, preheat your oven to 400°F.
Lightly grease a baking dish with non-stick cooking spray.
Place the salmon in the prepared dish, skin-side down if it has skin. Season both sides of the salmon with a generous pinch of salt and a crack of black pepper to enhance its natural flavors.
In a small saucepan or microwave-safe bowl, melt the butter. Stir in the minced garlic, lemon zest, lemon juice, and chopped dill. Allow to cool for a minute or two, just so it's not piping hot when you pour it over the fish.
Drizzle the lemon-dill butter evenly over the salmon. Arrange the lemon slices on top.
Bake the salmon in the preheated oven for 12–15 minutes. The exact time will depend on the thickness of your fillet.
Remove from the oven and let rest for a few minutes. Serve and enjoy