Place the chicken breast between two sheets of parchment paper and pound to an even half-inch thickness.
Place the chicken in a shallow bowl and pour the buttermilk over it, ensuring it is fully coated; marinate for at least 15 minutes.
In a separate shallow dish, whisk together the whole wheat flour, smoked paprika, garlic powder, sea salt, and black pepper.
Remove the chicken from the buttermilk, letting excess drip off, and dredge thoroughly in the flour mixture, pressing the coating firmly into the meat.
Lightly brush or spray the chicken with the extra virgin olive oil.
Place the chicken in an air fryer basket and cook at 375°F for 12 to 15 minutes, flipping halfway through, until the exterior is golden and the internal temperature reaches 165°F.
While the chicken cooks, whisk the Greek yogurt and Dijon mustard together in a small bowl to create a healthy spread.
Lightly toast the sprouted grain bun in a pan or toaster.
Assemble the sandwich by spreading the yogurt sauce on the bottom bun, followed by the lettuce leaf, the crispy chicken breast, and the dill pickles before topping with the other half of the bun.