Preheat the oven to 425˚F.
Place the salmon filet on a parchment-lined baking sheet on top of a few lemon slices, or put the lemon slices on top of the salmon.
Sprinkle with dill and salt and bake for 10 minutes, or until the edges flake with a fork, but the middle is still moist.
Meanwhile, whisk together the sauce ingredients (this part can be done up to 3 days ahead of time).
Serve the salmon topped with the dill sauce, with rice or boiled new potatoes (the sauce is also delicious on these) and salad or steamed veggies.