Stir the Greek yogurt and lemon juice together in a small bowl to create a tangy marinade.
Coat the chicken breast in the yogurt mixture and let it rest for 10 minutes.
Mix the arrowroot powder, smoked paprika, garlic powder, salt, and pepper in a separate dish.
Press the marinated chicken into the arrowroot mixture until fully coated.
Lightly brush the chicken with avocado oil and air-fry at 400°F for 12 minutes.
Combine the oat flour, egg white, and water in a bowl, whisking until the batter is smooth.
Pour the batter into a preheated waffle iron and cook until the exterior is crisp.
Serve the crispy chicken atop the warm waffle and finish with a drizzle of maple syrup.