Finely slice the garlic and chillies. Zest and juice the lemon.
Set a large frying pan over a medium heat and add the olive oil and butter. Once foaming, add the garlic, chillies and gochugaru. Cook for 2-3 mins until soft, then add the prawns. Cook for 90 seconds on each side until pink all the way through, then finish with the lemon zest and juice and season with salt and pepper. Set aside.
Remove the skin from the salmon fillets and add to a large mixing bowl along with the petit pois, edamame, sliced spring onions, light mayo, sesame seeds, prawns and cucumber. Using a pizza cutter, smash up the mix until evenly cut and well combined. Cut the avocado into large chunks and fold through. Season with salt and pepper.
Toast the sourdough. Pile the smash on top and finish with a drizzle of chilli oil and a scatter of sesame seeds.
