Position a rack in the middle of the oven. Preheat oven to 375°F | 190°C. Line a baking tray / sheet with a large piece of foil, big enough to fold over and seal to create a packet (or 2 long pieces of foil over lapping each other lengthways to create your salmon packet, depending on the width of you fillet).

In a small saucepan, melt the butter over low-medium heat. Add the garlic and cook until fragrant (1 minute). Turn off heat; whisk in the lemon juice and brown sugar.

Place the salmon onto lined baking tray | sheet. Season with salt and pepper to taste. Pour the lemon butter over the salmon, and using a spoon, spread evenly over the salmon. Sprinkle with parsley and dill. Arrange lemon slices over the salmon. Fold the sides of the foil over the salmon to cover and completely seal the packet closed.

Bake until cooked through (about 12-15 minutes, depending on the thickness of your fish and your preference of doneness). Open the foil, being careful of any escaping steam, and grill / broil under the grill / broiler for 2-3 minutes on medium heat. Garnish with extra parsley if desired and serve immediately.