Pat the ahi tuna steaks dry with a paper towel.
Season the tuna on both sides with salt and pepper. Dip the tuna in egg and then coat well with the panko. Refrigerate for 10 minutes.
Cut and form the goat cheese into equal round cakes. Dip in egg and coat well with breadcrumbs. Place in the freezer until ready to fry.
Heat the oil in a non-stick pan on medium heat until very 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-degree oven on a baking sheet for 5 - 6 minutes so the tuna does not burn)
Remove the tuna from the pan to a cutting board and allow to rest for 3 minutes before slicing.
Fry the goat cheese to golden brown on each side, about 2 minutes per side.
In a blender or food processor add the avocado, lime juice, sour cream, and cilantro. Blend until smooth. Season with salt and pepper to taste.
Cut the goat cheese in half and serve with the avocado puree and sliced tuna.