Remove the salmon from the refrigerator and let it stand at room temperature for 10 minutes while you prepare the other ingredients. Heat the BBQ to medium (about 180C) – see Notes for cooking in the oven instead. Lightly coat a piece of kitchen foil, large enough to wrap around the salmon and seal it, with olive oil or spray oil. Pat dry both sides of the piece of salmon with kitchen roll, then place it in the centre of the oiled foil.
In a small bowl, stir together the brown sugar, chipotle chilli powder, lime zest, and salt. Brush the salmon with the extra virgin olive oil and lime juice. Sprinkle with the chipotle seasoning mixture, rubbing if needed to coat the salmon evenly.
Fold the sides of the kitchen foil up and over the top of the salmon until it is completely enclosed. If your piece of foil is not large enough, place a second piece on top and fold the edges under so that it forms a sealed packet. Leave a little room inside the foil for air to circulate.