Mix honey, soy sauce, and sesame oil for the marinade. Grate garlic and ginger into the mixture. Slice the chicken breast into thin strips and marinate for 10 minutes.
Halve the cucumber lengthwise, remove the seeds with a spoon, and cut the cucumber flesh, carrot, and kohlrabi into thin strips using a julienne peeler. Slice the spring onion into rings. Mix the vegetables with some of the spring onion rings and sesame oil. Season with salt.
Cut the bread horizontally in half. Press the crumb of the bottom half slightly and fill it with the salad. Fry the chicken with the marinade in a pan until cooked through. Place the meat on top of the salad. Drizzle with Sriracha mayonnaise and sprinkle with the remaining spring onions. Cover with the top half of the bread and serve immediately or chilled.