If you are using wooden skewers, put them into a large bowl or roasting pan and cover with cold water. Leave to soak for 30 minutes. This is so they don't burn later.
Start by making the marinade. Put all the ingredients into a large bowl and mix well. Cut the salmon into chunky bite sized pieces and add to the bowl. Using your hands, toss the salmon to thoroughly coat with the marinade. Cover the bowl and place into the fridge for 30 minutes.
Meanwhile make the relish. Put all the ingredients into a food processor and pulse a few times to combine, keeping it chunky. Taste a small amount and add more salt if needed. Transfer to a small bowl.
Assemble the brochettes. Divide the onion wedges into individual layers. Now take a layer of the onion, thread it onto the skewer and push it up towards the ring end. Follow with a cube of salmon, sliding it towards the end to make way for more. Repeat until you have used up all the salmon pieces.
Place your griddle over a burner and, when it's hot, wipe just a little avocado or coconut oil over the top to stop the salmon sticking. Put the skewers on top of the griddle and cook for around 4 minutes, depending on their size, turning them half way through. Sprinkle a little sea salt over the brochettes and serve with the relish and some lightly dressed green leaves.
Notes
Try to find a piece of salmon from the thick end of the fish, rather than the tail which tapers off and is too thin to use. Brochettes always work and look better, cook more evenly and are less likely to fall apart when the pieces are the same size.
Recipe by Autoimmune Wellness at https://autoimmunewellness.com/turmeric-salmon-brochettes-with-a-chunky-tapenade-relish/