Combine 125gm butter, herbs and garlic in a small bowl, season to taste and set aside until required.
Place chicken pieces between two pieces of plastic wrap and flatten to 5mm thick with a meat mallet. Dip in flour, then eggwash, then breadcrumbs and shake off excess in between.
Heat half the oil in a large frying pan over medium heat, add half the remaining butter, then, when foaming, add half the chicken and cook, turning once, until golden and cooked through (5-7 minutes each side). Wipe pan clean and repeat with remaining oil, butter and chicken. Season to taste, set aside on absorbent paper and keep warm.
Meanwhile, heat herb butter in a small saucepan over medium heat until melted (2-3 minutes). Add lemon rind and juice, drizzle over chicken and serve with steamed green beans and lemon wedges.