1In a shallow dish, mix breadcrumbs with Parmesan, salt, and pepper. In another dish, beat the egg.
2Dip each cutlet first in egg, then in the breadcrumb mixture, pressing firmly to adhere.
3Lightly spray the breaded cutlets with oil on both sides. Place them in a single layer in the air fryer basket. Cook at 180°C (350°F) for 10–12 minutes, turning halfway, until golden and crispy.
4Meanwhile, make the tonnato sauce: in a small blender or food processor, combine drained tuna, capers, anchovies, mayonnaise, and lemon juice. Blend until smooth and creamy. Taste and adjust salt and pepper if needed.
5Cook the frozen peas according to package instructions (steam, boil, or microwave). Drain well.
6Serve the Milanese cutlets hot, generously topped with tonnato sauce, alongside the peas. Garnish with a drizzle of olive oil and extra capers if desired.