Add garlic. Cook 2 minutes or just until garlic is lightly browned.
Remove from heat, and stir in rosemary and thyme; set aside.
Brush bottom and sides of a 9" cast-iron skillet with 2 tablespoons oil. Arrange enough potato slices to cover bottom of skillet, overlapping slices; drizzle with one-third herbed garlic butter.
Sprinkle with 1/4 teaspoon salt and 1/4 teaspoon pepper. Repeat procedure twice with remaining potato, herbed garlic butter, salt, and pepper.
Brush a piece of aluminum foil with melted butter; press foil firmly, buttered side down, onto potato slices.
Bake at 400 for 1 hour and 10 minutes.
Remove from oven, and using an oven mitt, press down firmly on the aluminum foil-covered potatoes.
Remove aluminum foil, and place skillet on stovetop over medium heat. Cook 5 minutes.
Remove from heat; let stand 2 minutes. Invert potatoes onto a plate, coaxing potatoes loose from skillet with a spatula.
Bake potatoes Anna earlier in the day; invert onto an ovenproof plate, and cover loosely with foil. Just before serving, uncover and reheat at 400 for 10 minutes.