Step 1Combine the vinegar, salt and sugar in a small bowl until dissolved. Add the cucumber, toss and set aside to pickle for 15 minutes. Drain and squeeze to remove the excess moisture.
Step 2Meanwhile, combine soy sauce, mirin, brown sugar, ginger and garlic in a large, shallow dish. Add the tofu slices; toss to coat, and set aside to marinate for at least 10 minutes.
Step 3Heat sesame oil in a large non-stick frying pan over medium-high heat. Add tofu to pan (reserving remaining marinade); cook for 1 minute, turning halfway, or until it is lightly golden. Reduce heat to medium-low and pour in the rest of the marinade. Simmer, tossing tofu to coat for a further 2 minutes, or until the sauce is slightly thickened. Sprinkle tofu with sesame seeds.
Step 4Spread the base of each roll with avocado. Top with cos lettuce, grated carrot, sticky soy tofu, pickled cucumber and alfalfa sprouts. Top with roll lid and serve.