Preheat oven to 400F.
In a large round casserole dish, use softened butter to coat the dish.
In a large mixing bowl, mix garlic, rosemary, sage, thyme, miso and remaining softened butter.
Peel and slice sweet potatoes to ¼” thickness.
Add sweet potatoes to bowl of herbs and toss to coat.
(I use plastic gloves for this aspect). Arrange the sweet potatoes on an angle or upright in a circular arrangement around the round casserole dish.
Add any remaining miso and butter herb mixture in dots across the top of the sweet potatoes.
Place lid on casserole dish or seal aluminum foil on the top of casserole dish to allow for steaming.
Bake in oven for 40 minutes or until the sweet potatoes are fork tender.
Leave lid on casserole dish if prepping other items, serve hot.