Preheat the grill to high. Peel the cucumber into ribbons with a vegetable peeler. Thinly slice the tomato.
Step 2 — Prep chicken
Whisk half the ayam goreng paste* and a generous drizzle of oil in a large bowl until combined. Cut the chicken on an angle into 1cm-thick slices. Add the chicken to the ayam goreng oil and stir to coat.
Step 3 — Cook chicken
Heat a medium frypan over medium-high heat. Add the chicken, including the ayam goreng oil in the bowl, to the pan (make sure you add all the ayam goreng oil for maximum flavour). Cook for 2 mins each side or until golden and cooked through. Remove the pan from the heat.
Step 4 — Grill buns
Meanwhile, halve the buns through the middle. Put on an oven tray, cut-side up, and grill for 2-3 mins until lightly toasted.
Step 5 — Make salad
Put the wasabi (if you don't tolerate heat, omit the wasabi) in a large bowl, add 2 tsp white vinegar and 2 tsp extra virgin olive oil, season with salt and whisk to combine. Add the salad leaves and cucumber and toss to coat.
Step 6 — Assemble burgers
Divide the chicken, tomato and three-quarters of the salad among the bun bases and drizzle with any pan juices, then sandwich with the bun tops. Serve the burgers with the remaining salad.