Flatten chicken breasts using a meat tenderizer to between 1/4 and 1/2-inch thickness. Add flour and chicken breasts to a large bag. Toss to coat well. Set aside.
Combine lemon zest and seasonings in a small bowl. Season both sides of each chicken breast well.
Melt butter in a 10-inch skillet over medium-high heat. Add seasoned chicken breasts, cooking 2-4 minutes per side. Remove chicken breasts from skillet. Cook lemon slices for 30 seconds on each side. Return chicken to pan, cook for an additional minute.