1-Begin with the first step: Prepare the marinade by zesting and juicing one lemon into a large bowl. Add 1/4 cup olive oil, crushed garlic, 1 1/2 teaspoons Italian seasoning, 1/2 teaspoon red pepper flakes if using, and 1/4 cup chopped parsley. Whisk to combine and set aside for that fresh, zesty base.

2-Key Preparation Steps: Next, slice each chicken breast horizontally to create two thin cutlets and optionally flatten them with plastic wrap and a kitchen mallet for even cooking. Pat the chicken dry with paper towels, season both sides with kosher salt and black pepper, then add to the marinade. Turn to coat, cover, and refrigerate for 30 minutes up to 2 hours to let those flavors soak in.

3-Cooking: Heat 2 tablespoons olive oil in a large skillet over medium heat. When shimmering, arrange chicken in the skillet without crowding and cook approximately 4 minutes per side until golden brown and nearly cooked through. Remove chicken when internal temperature reaches 160°F, tent with foil, and rest for 5 minutes to reach 165°F. Slice the remaining lemon during resting and garnish with chopped parsley and lemon slices before serving whole or sliced.