Tuna-Salad Hand Rolls

In a medium bowl, stir together tuna, mayonnaise, lemon juice, and cilantro until combined; season with salt and pepper. In another bowl, toss together cucumber and carrot matchsticks with salt, sugar, and vinegar; set aside.

To assemble hand rolls, pat rice into the middle of nori sheets; top with tuna, vegetables, and avocado; roll firmly to seal. Serve with soy sauce, pickled ginger, and sambal oelek.