How to Make It
Preheat oven to 200°F. Pulse breadcrumbs in the bowl of a food processor until finely ground, about 10 times. Add cayenne, ground mustard, and 1 teaspoon of the salt; pulse once to combine. Transfer to a large shallow dish; set aside. Stir together flour and 1 teaspoon of the salt in a second shallow dish. Stir together eggs and 2 tablespoons water in a third shallow dish. Working in batches, dip chicken strips in flour, followed by egg wash, and then panko mixture, pressing to adhere. Return to egg wash, and back to panko, pressing again to adhere.
Pour oil to a depth of 1 to 2 inches in a large 12-inch cast-iron skillet over medium to 350°F. Working in batches of 10 to 12 strips, carefully place in hot oil, careful to not overcrowd skillet; cook, until breading is golden brown and very crispy, 1 to 1 1/2 minutes total per batch, turning once halfway through. Remove strips from skillet, and place on a wire rack set inside a rimmed baking sheet lined with parchment paper. Sprinkle with a pinch of remaining 1 teaspoon salt. Place in preheated oven to keep warm while repeating frying process with remaining strips. (Adjust heat under skillet as needed to maintain oil temperature of 350°F while frying.)
Transfer warm chicken strips to a serving platter, and serve immediately with dipping sauce of choice.