Cut the yuzu (or lemon or lime) in half. Cut one half into slices, and keep the other half to use in the pickling marinade.Cut the dried chili into flakes, removing the seeds if you don’t want it too spicy.Mix the marinade ingredients together.Peel the carrots and cut into 5cm lengths, then julienne.Peel and julienne the ginger.Thinly slice the onion.
Cut the salmon filets into large bite-sized pieces and season with salt and pepper. Set aside for 2-3 minutes to draw out excess moisture, then pat dry and lightly coat with flour.
Pour about 3cm of vegetable oil into a deep saucepan and bring to a temperature of 180-190C. Deep-fry the salmon in batches for about 3 minutes per batch, making sure not to overcrowd the pan. When the salmon is crispy, remove from pan and drain on a paper towel lined rack.
Put the salmon in the marinade while still hot, top with vegetables and sliced yuzu, and set aside for at least 30 minutes to cool. Once cooled to room temperature, either serve as is or refrigerate – it tastes even better the next day!