Lay the salmon on baking paper or alfoil, skin side down (if the salmon has skin). Fold up the sides of the baking paper or alfoil to create a "boat" for the salmon. Season the salmon with salt and pepper. Lay the lemon slices on the salmon.
Set up your barbecue for indirect cooking. Please refer to your handbook for further instructions. Preheat your barbecue for roasting.
Whilst the barbecue is preheating, in a saucepan over medium heat on the stove top, cook the butter and shallots until the shallots have just started to golden. Add the garlic and herbs, cook for a further 5 minutes or until the shallots are golden.
Once the barbecue is preheated, make adjustments to the burner control(s) for the roasting setting. Place the salmon on and cook for 20 to 25 minutes, or until cooked to your liking. Ten minutes into the cooking time, pour the herb and shallot butter over the salmon.
Grill the lemon halves over direct heat for 5 minutes or until lightly charred and caramelised.
Once the salmon has cooked to your liking, remove from the barbecue and finish with a squeeze of grilled lemon.