1. Scrape the scales from the skin of the salmon, wash well and dry with paper towels.
2. Brush 4 squares of foil lightly with oil. Place a piece of salmon on each. Sprinkle with lemon juice, herbs, salt and pepper. Add a knob of butter.
3. Draw up the foil and pinch the edges together to seal well. Transfer to a baking sheet. Place in a preheated oven and cook for 20-25 minutes.