Prepare the Spicy Tuna: Season ahi tuna filets with salt and pepper. Finely chop the tuna into small cubes. Mix with mayonnaise, sesame oil, and sriracha in a bowl until well combined. Adjust sriracha to your spice preference.

Prepare the Cucumber: Slice the cucumber into thin, flexible strips using a mandolin or a sharp knife. The strips should be wide enough to hold the fillings, but not too thick.

Assemble the Rolls: Lay cucumber strips flat. Add a small amount of spicy tuna mixture, a few slices of avocado, and pickled carrots at one end of the strip. Roll the cucumber around the fillings and press gently to secure.

Serve: Slice the rolls into bite-sized pieces and serve with soy sauce for dipping.