Peel 3 garlic cloves + smash slightly with a knife

Pat chicken dry then using a meat mallet, pound until the breast is equal thickness; rub with 1 tsp oil + salt/pep; heat 1 tbsp oil in a skillet over med-high until just smoking; sear chicken one side, 3-4 min, until golden then flip + turn heat to med-low; add butter, rosemary + garlic

When butter is foamy, tilt skillet + spoon butter over the chicken until cooked through, 3-5 min; let chicken rest 5 min

Add arugula to a large bowl, drizzle on 2-4 tbsp dressing + toss to combine; divide salad + chicken to plates then drizzle chicken with pan drippings + garlic