In a small bowl combine yogurt, a pinch sea salt, lemon juice, cilantro, and ranch dressing. Cover and refrigerate until needed.
Add 1 ½ inch of oil in a medium saucepan and heat the oil until it reaches 375 degrees. You can also use a deep fryer for this. While the oil is heating, in a shallow plate or pie dish mix flour with a ½ teaspoon of salt. In another shallow plate, add the Panko bread crumbs, and in an additional shallow plate, add the eggs.
Sprinkle avocado slices with the remaining ½ teaspoon of salt. Roll each avocado slice first in the flour mixture, then dip in the egg mixture, and roll in the Panko breadcrumbs to coat. Place onto a baking sheet in a single layer.
Add avocado slices to the hot oil in the saucepan or deep fryer and fry in batches at 375 degrees until golden brown (this should only take about 30-60 seconds). Drain on paper towels. Sprinkle with grated parmesan cheese if desired and serve with cilantro ranch dipping sauce.