Preheat the oven to 220°C/ 200°C fan/ gas mark 7/ 425°F
Peel and slice the onions or shallots
Cut 4 slices off the lemon (about half the lemon) and juice the rest
Cut the foil to 30 x 45cm/12"x18"
For the Chicken Parcels:
Lay out the pieces of foil and divide the onions between them, placing the onions in the centre
Pat the chicken with paper towel to dry it. Put a chicken leg on top of the onions
Spray or drizzle the oil onto the chicken and rub in gently with your fingers. Sprinkle salt and pepper over the chicken
Drip the lemon juice over the chicken (about 1-1 ½ teaspoon per joint). Arrange the herbs and lemon slice on top of the chicken
Pull the longest sides of foil over the chicken and make a double fold. Make a double fold in each side of the foil so that you have a neat parcel
Arrange the four parcels on a baking tray and cook for 30 minutes
Carefully unwrap the foil VERY CAREFULLY starting at a side, so that the chicken is mostly uncoveredBEWARE! Very hot steam will come out of the parcel so keep your fingers away from the opening
Return the tray to the oven and cook uncovered for a further 15-20 minutesIf you have a meat thermometer, use it to check when the chicken is doneThe internal temperature is at least 75°C (although I prefer to leave mine to 85°C)
If you are serving cold, e.g. for a picnic, drain some of the juice away and re-wrap the chicken. Once it has cooled, refrigerate until needed.