Put the ginger, garlic, chilli, yuzu juice, oil and salt and pepper into a bowl and stir. Reserve 2 tablespoons of the dressing. Sit the salmon fillets on top of the leeks, season with salt and ...
There isn’t a substitute for it, but if you can’t find it at your local Japanese market (where you can also buy bottled yuzu juice), use light soy sauce diluted with some water to taste.