Melt butter in a small pan and add corn, diced red pepper, and red onion. Saute until crisp-tender, about 3 minutes. Add cayenne pepper, milk, vinegar, and cream cheese. Cook 1 minute, stirring constantly, to melt the cream cheese. Remove from heat and stir in parsley. Let cool to room temperature.
Pound pork between 2 pieces of plastic wrap to about 1/4-inch thickness. Sprinkle with salt and pepper.
In a shallow dish, whisk together eggs and water. Place the Wondra on a plate and the Panko crumbs on another plate.
Coat both sides of pork in Wondra, dip in egg mixture, and then coat with Panko crumbs.
Place 2 tablespoons of oil in a nonstick pan and heat over medium-high heat. Add half of pork to pan and cook about 4 minutes per side, or until bowned and cooked through. Remove to a paper towel-lined plate. Add remaining oil to pan and cook remaining pork.
To serve, place a lettuce leaf on bottom of each bun, top with 2 or 3 slices of pork and corn relish.