Roughly chop the salmon fillets. Put half into a food processor and blitz to a paste. Add the miso, ginger, lime zest, the rest of the salmon and 1 tbsp of soy sauce. Pulse very briefly until roughly combined.
Tip the mix into a bowl and stir through the panko breadcrumbs. Shape into four burgers and chill whilst you make the smacked cucumbers.
Get a rolling pin or something heavy and hit the cucumber until it has collapsed and starts to break. Cut into random diagonal pieces. Place in a bowl and stir in the salt. Leave to sit for 10 minutes to draw out some of the water from the cucumber.
Crush in the garlic cloves and mix with 1 tbsp of Sriracha sauce, 2 tbsp olive oil, 1 tbsp of soy sauce, sugar and lime juice.
Mix the remaining Sriracha sauce with the mayonnaise.
Pour a drizzle of oil into a non-stick frying pan. Fry the salmon burgers for 3 minutes on each side.
Drain the water off the cucumbers and mix with the dressing. Cut the buns in half, spread the bottom of each bun with the sriracha mayo. Top each with a salmon burger and pile on the smacked cucumber slaw. Drizzle over the dressing.
