Heat EVOO and 2 tablespoons butter in a large pan over medium-high heat. When butter foams, add drummers and season with salt, pepper and herbs. Shake pan and brown chicken all over (brown in two batches, if necessary).
Add all of the chicken back to the pan and reduce heat to medium. Cook 15-20 minutes to cook through. Remove drummers to a warm platter and cover with foil.
Add remaining butter to pan and melt. Add garlic and chili peppers, stir 2 minutes then add zest of 1 lemon and juice of both to the pan. Swirl to combine, pour over drummers and garnish with parsley and scallions.