In a wide shallow bowl, beat the eggs with the mustard, cayenne, ½ teaspoon salt and ¼ teaspoon pepper. In another wide shallow bowl mix the the panko with the Parmesan. Dip the chicken cutlets in the egg mixture, and allow any excess to drip back into the bowl. Dredge the cutlets in the panko mixture, pressing the chicken down so that the crumbs adhere. Place the cutlets on a baking sheet.
In a large skillet (the largest you have) heat ½ cup olive oil over medium high heat until hot. Cook the chicken in batches, without crowding the cutlets in the pan, until they are nicely browned on both sides and cooked throughout, 3 to 4 minutes per side. Transfer the chicken to a serving plate, or place 2 cutlets on 4 individual plates.
While the chicken is cooking, place the arugula, tomatoes, parsley, and chervil (if using) in a medium bowl. Drizzle over the remaining tablespoon olive oil and the lemon juice, and season with salt and pepper. Toss, and place a mound of the salad on top of each cutlet, or just strew the whole salad mixture over the chicken on a serving platter. Top the salad with the shaved or grated Parmesan and serve.
Notes
If you are planning to serve this Chicken Milanese at room temperature, let the chicken cool before topping it with the salad, so the salad won’t wilt too much and the chicken won’t get soggy.