Hello Mark. Yes, you can cook frozen chicken breasts straight from the freezer without thawing them first, though the oven is safer and more reliable than a pan for even cooking.
Preheat your oven to 425°F (220°C). Place the frozen chicken breasts in a single layer in a baking dish, add a splash of chicken broth or olive oil to keep them moist, and season them well.
Cover the dish tightly with foil to trap the steam and bake for about 30 to 45 minutes, then remove the foil for the last 10 minutes to let them brown slightly. Always check with a meat thermometer to ensure the internal temperature reaches 165°F (74°C) in the thickest part.