Preheat the oven to 350 degrees.
Mix together the oil, garlic, dill, and salt in a small bowl.
Cut the lemon in half, and squeeze one half into the oil mixture. Cut the second half in thin slices.
Spoon the mixture over the fish fillets. Then place 1-2 slices of lemon on top of each fillet. Place on a baking sheet and bake 8-12 minutes, depending on thickness of the fish.
Place under the broiler for 2 minutes. Serve hot or cold.