How to Make It
In a large saucepan, cover the potatoes, garlic and bay leaves with 2 inches of water and bring to a boil. Cook until the potatoes are tender, about 30 minutes. Drain the potatoes; discard the garlic and bay leaves.
Meanwhile, in a small skillet, heat the olive oil. Add the walnuts and toast, stirring, until golden, about 5 minutes. Add the miso and stir until coated. Transfer to a plate to cool.
Transfer the potatoes to a large bowl and mash with a fork until chunky. Add the walnuts, cheese and onion and mix well. Transfer to a platter and drizzle with the maple syrup and vinegar. Garnish with mint and serve.