Melt the butter in a 10- or 12-inch skillet over medium heat. Add the oats and toast, stirring occasionally, until golden and fragrant, about 2 minutes. Combine the water and milk in a medium saucepan. Bring it to a simmer. \tStir the toasted oats into the simmering liquid. Reduce the heat to medium-low and simmer gently until the mixture is very thick about 20 minutes. \tStir in the salt, brown sugar, carrot, coconut, raisins, cinnamon, ginger, and nutmeg.\u00a0 Continue to simmer, stirring occasionally, until all of the liquid has been absorbed and the oatmeal is creamy, about 10 minutes more. Remove from the heat and let stand 5 minutes before serving. Then top with chopped walnuts. \t*To make this vegan\/dairy-free, use coconut milk and coconut oil in place of the milk and butter. \t** This recipe can be made in advance and reheated before serving. When reheating, stir in an additional splash of milk to help loosen the cooled oats.