Preheat oven to 400°F. Line a baking tray with parchment paper and set aside. Prepare squash by cutting into 1-inch circles or into 2-inch long sticks.
Prepare a dredge station, by placing flour in one plate, egg whites and soy sauce in a second plate and panko bread crumbs in a third plate. Whisk together egg whites and soy sauce until combined and egg whites are a little frothy.
Dip squash into flour, then egg and then panko bread crumbs. Place on parchment-lined sheet.
Roast at 400°F for 25 minutes until golden brown. Serve with sriracha mayo or your favorite dipping sauce.