Preheat oven to 400º. Lightly grease the bottom of your baking dish with olive oil. Rinse and thoroughly dry salmon. Season generously with sea salt and black pepper.
Mix butter, zest and dill together. Dot half of the butter onto salmon, spacing it out evenly. Bake for about 10 minutes and check for doneness with a discreet fork and knife. Depending on the thickness of your fish, you may add more time. I always take mine out when it is is slightly undercooked in the center. The residual heat of the flesh will continue cooking a bit, so if you wait until it's completely done, you'll end up with dry, overcooked salmon.
Once out of the oven, squirt lemon juice all over the fish. Add more if you like. Then dollop the remaining butter on the fish and let it melt. Serve now or at room temperature. It's lovely both ways.
Recipe by Mamaguru at http://mamaguru.com/baked-salmon-with-lemon-dill-butter/