Add chicken breasts, seasonings (garlic powder, onion powder, salt and black pepper) and egg into a food processor and process until chicken is fully minced.
Line a large baking sheet with parchment paper. Use a 1 ounce (2 tablespoons) cookie scoop to divide chicken mixture into 20 portions. Shape each portion of chicken into nugget shape.
Cover baking sheet with plastic wrap and chill the nuggets for 1 hour in the fridge or until firm to touch.
In a shallow bowl, add 1/2 cup cornstarch and set aside. In a separate mixing bowl, add the flour, remaining cornstarch, baking soda and seasonings (paprika, garlic powder, onion powder, salt and black pepper). Mix to combine before whisking in the sparkling water.
In a heavy bottom pan, heat the oil to 350F under medium high heat. Remove chilled nuggets from the fridge.
In batches, coat the nuggets in the cornstarch before adding in the wet batter to coat. Shake off excess batter and add the coated nuggets into to the heated oil.
Fry the nuggets until golden brown, about 3-4 minutes per side. Transfer to a wire rack placed over a paper towel lined baking sheet to catch any excess oil.
Serve nuggets immediately with fries (optional) and your favorite sauce. Enjoy!