In a small sauce pot mix together the water and cornstarch. Whisk or stir with a fork until smooth.
Add all remaining ingredients to the sauce pot and stir to combine.
Cook on medium heat until the mixture begins to boil and thicken.
Cook for 5-10 minutes until it thickens and coats the back of a spoon.
Cool and store in an air tight jar in the fridge for up to 7 days and use in your favorite recipes.
Notes
Mirin is a Japanese sweet rice wine that adds a mild acidity to a recipe. It is similar to sake, but lower in sugar and alcohol. It provides a umami flavor to savory dishes. You can substitute the 3 tablespoons of mirin in this recipe with 3 tablespoons of water mixed with 1 teaspoon of white sugar.