Early in the day (at least 4 hours in advance) mix the rosemary, thyme, garlic, salt, pepper, lemon zest, lemon juice and olive oil together in a small bowl. Rinse the chicken breasts and pat them dry.
Press the herb mixture into the flesh of the chicken on all sides. Place chicken on a sheet pan. Cover with plastic wrap and refrigerate for 4-8 hours.
Preheat the oven to 450˚F. Lightly grease a sheet pan with oil.
Combine potatoes, olive oil, salt and pepper in a medium-size bowl. Toss to coat. Turn potatoes out onto prepared sheet pan in an even layer.
Place in oven and roast for 15 minutes. Remove from oven.
Add the chicken breasts to the pan, skin side up in between the potatoes. Tuck lemons around chicken and potatoes. Roast for about 30-45 minutes longer, or until the breasts reach 160˚F* in the thickest part. If breasts vary greatly in size, you may need to remove the smaller ones 5 minutes before the larger ones. (If you're using skin-on, boneless breasts, baking time will be about 5-10 minutes less, so just add them after the potatoes are in for 20 minutes and check the temperature after 25 minutes.)
Remove from oven and cover chicken loosely with foil. Allow to rest for 5 minutes before serving.