Instructions

1. Arrange a rack in the middle of the oven and heat to 200C.
2. Grease a 20x30cm baking dish with butter or cooking spray; set aside.
3. Place the milk, butter, garlic, and bay leaf in a small saucepan and bring to a simmer over low heat.
4. Meanwhile, combine the beans, nutmeg, salt, and pepper in a small bowl.
5. Evenly distribute about half of the potatoes over the bottom of the baking dish. Sprinkle with half of the salt, beans and herb mixture. Add the remaining potatoes in an even layer. Sprinkle with the remaining seasoning.
6. Remove the bay leaf from the cream and discard. Pour the cream and garlic over the potatoes. Push down to submerge them as much as possible. The potatoes won't be fully submerged - that's okay. Cover tightly with aluminum foil.
7. Bake for 15 minutes. Uncover and bake until the sweet potatoes are tender, about 15 minutes more. Remove the baking dish from the oven. Turn on the oven's grill. Sprinkle the cheese over the top of the potatoes. Grill until the cheese is melted and the top is lightly browned, 3 to 5 minutes. Let the sweet potatoes cool for about 10 minutes before serving and garnish with fresh mint leaves.