Put one tablespoon of oil in a saucepan over a medium heat. Chop the rainbow chard into 1-2 inch pieces and add to the pan. Sauté for 1-2 minutes.
Add the chickpeas (if you have 2 tins, drain one. Pour the water from the other into the pan along with the chickpeas). Cook for another 2-3 minutes, stirring regularly.
Add the butter to the chickpeas. Stir until melted in, then taste before seasoning with salt and pepper. Turn the heat down to low before cooking the salmon.
Put the remaining tablespoon of oil into a frying pan over a medium heat. Season the salmon with salt then put them skin side down in the pan. Cook for 5 minutes before flipping and cooking for another 30 seconds.
To serve, spoon the chickpeas into bowls then top with the salmon.