Using meat mallet or rolling pin, flatten chicken between sheets of plastic wrap to thickness of 1/2 inch. Whisk eggs in medium bowl to blend. Mix panko, 2 tablespoons parsley, oregano, salt, and pepper on plate. Dip chicken in beaten eggs; turn to coat. Dredge in breadcrumb mixture, coating completely.
Heat 3 tablespoons oil in large nonstick skillet over medium heat. Add chicken and sauté until golden brown and cooked through, about 5 minutes per side. Transfer chicken to plates; sprinkle with lemon juice. Toss arugula with remaining 1 tablespoon oil in medium bowl to coat; sprinkle with salt and pepper. Mound salad atop chicken.
