Prepare the cucumber boats

• Halve the cucumber lengthways and scoop out the seeds with a spoon.
• Season lightly with salt and set aside.

Cook the prawns

• Heat the sesame oil in a frying pan over medium heat.
• Add the prawns and cook until pink and just firm.

Make the spicy sauce

• Mix the mayonnaise with the sriracha in a bowl.
• Toss the cooked prawns through the sauce.

Fill and serve

• Spoon the spicy prawns into the cucumber boats.
• Scatter over the spring onion and toasted sesame seeds and serve.