Combine in a small saucepan, the orange juice and cardamom pods. Bring to a boil and reduce to half a cup. Keep warm and whisk in the cubes of cold butter, set aside in a warm place until needed.
Whisk together the chilli paste, mirin, olive oil and all but a pinch of salt. Coat the salmon portions with the mix and grill on a pre-heated bbq plate for 2 minutes. Turn over and grill for a further 3 minutes, keeping the centre moist and glossy.
Smear the plate with two tablespoons of the sauce, top with a salmon portion and finish with the tomatoes, mozzarella, flowers (if available), cress and a scattering of salt flakes.