Cook the rice according to the instructions on the package. Once cooked, place in a shallow bowl, season with salt and toss with rice wine vinegar, set aside to cool.
Pat the ahi tuna steaks dry with a paper towel. Season both sides with salt and lemon pepper seasoning.
Heat 1/4 of the oil in a non-stick pan over medium heat until hot.
Sear the tuna for 1 minute on each side for rare; 2 minutes on each side for medium-rare; or 3 minutes on each side for medium (if desiring medium-well or well-done sear the outside of the tuna in the pan 1 minute per each side and finish in a 350°F oven on a baking sheet for 5-6 minutes so the tuna does not burn). Place on a cutting board, and allow to cool before chopping into small pieces.
If using the wonton: Add the remaining oil or more if needed in order to cover the bottom of the pan. Fry the wonton wrappers on each side to golden brown. Place on a paper towel lined plate to drain excess grease and season with salt.
Place the nori sheet shiny side down onto the bamboo mat (you can use parchment paper if you do not have a bamboo mat). Spread a layer of rice on the nori sheet (dampen your hands to prevent the rice from sticking). Place the chopped tuna, cucumber, avocado, and sprinkle with panko breadcrumbs. Gently roll up the nori sheet tightly, press firmly as you roll to make sure it's tight. Then set aside. (Repeat this process with any additional sushi rolls.)
In a bowl, whisk together all of the ingredients for the Yum Yum Sauce.
Slice the sushi rolls into 1/2 inch pieces, drizzle with Yum Yum sauce; serve with fried wontons, wasabi and pickled ginger if using.