Slice each chicken breast in half lengthwise. Thicker parts can be sliced one more time. This step eliminates the need to pound the meat. Sprinkle chicken on both sides with salt and pepper and transfer to a plate.
In a shallow plate add flour. Prep other ingredients. Everything has to be ready before you start cooking. Preheat large ceramic non-stick skillet on medium heat and swirl 2 tsp oil to coat.
Dredge chicken in flour on both sides and add to the skillet as many as you can fit.
Cook chicken for 4-5 minutes on each side and transfer onto a plate. Repeat with remaining chicken, adding more oil as necessary and reducing heat as skillet gets hotter.
Add 1 tbsp butter and garlic, saute for 20 seconds, stirring often. Add chicken stock, lemon zest and juice, 2 more tbsp of butter and bring to a boil while scraping the bottom. Cook for 2 minutes.
Add chicken back to the skillet and spoon lemon butter sauce over it. Alternatively, if you placed chicken in a serving dish after pan searing, you can pour sauce over it right there.
Sprinkle with parsley or basil and garnish with lemon slices, if desired. Serve warm with mashed potatoes, Instant Pot quinoa or cauliflower mash and simple green beans or cucumber and tomato salad.