Preheat oven to 425 degrees. In a food processor or blender, combine bread, walnuts, thyme and oregano; season with salt and pepper. Process until fine crumbs form. Transfer to a shallow bowl. In another shallow bowl, beat egg until frothy.
Slightly flatten thickest part of chicken so until chicken is a more uniform thickness (around 1/2” thick). Season chicken with salt and pepper. Dip each breast into egg, letting excess drip off, and then into crumb mixture, pressing to adhere. Crumbs.
In a large nonstick ovenproof skillet heat oil over medium heat. Add chicken and cook until lightly browned, 1 to 3 minutes. Carefully turn chicken over and put skillet in oven. Bake until chicken is golden brown and cooked through, 8 to 12 minutes.
To serve, thinly slice chicken, place on bed of greens with cherry tomatoes. Offer salad dressing on the side.