Slice the horse mackerel sashimi into 7mm diagonal pieces.

Trim the cilantro roots, chop 2/3 into bite-sized pieces, and finely chop the remaining 1/3. Julienne the carrot.

Place bean sprouts in a microwave-safe container with 1 tbsp water. Cover loosely with plastic wrap and microwave at 600W for 90 seconds. Rinse under cold water, drain, and squeeze out excess moisture.

Mix the sauce ingredients (lemon juice, fish sauce, olive oil, chili, salt, garlic paste) with the finely chopped cilantro in a bowl.

Dip rice paper in lukewarm water briefly. Layer lettuce, cilantro, bean sprouts, carrot, and horse mackerel (1/4 of each ingredient) on the rice paper and roll tightly. Repeat for 4 rolls.