Preheat the oven to 350 degrees F. Spray a baking dish with nonstick spray.
In a bowl, stir together the quinoa, milk, water, vanilla, cinnamon, salt and nutmeg. Pour it into the baking dish and bake for 20 minutes. Remove from the oven and stir well (to incorporate any of the milk laying on top), then bake for 15 to 20 more minutes until most of the liquid is absorbed.
While the quinoa is cooking, make the plums. Add the plums, water and honey to a saucepan over medium-low heat. Bring the mixture to a simmer and cook, stirring occasionally, until the plums are soft and juicy, about 5 minutes.
To serve the quinoa, scoop some into a bowl and pour milk over top. My favorite here is coconut milk! Add some yogurt and pistachios on too, then spoon some of the plums and juice over it. Devour.