How do you make the mustard sauce from japanese restaurants?

* 1/4 cup soy sauce

* 1/4 cup mirin

* 1/4 cup sake

* 2 tablespoons Dijon mustard

* 1 tablespoon sugar

* 1 teaspoon cornstarch

* 1 tablespoon water

Instructions:

1. In a small saucepan, combine the soy sauce, mirin, sake, Dijon mustard, sugar, and cornstarch.

2. Bring to a boil over medium heat, stirring constantly.

3. Reduce heat to low and simmer for 5 minutes, or until the sauce has thickened.

4. Remove from heat and stir in the water.

5. Serve immediately with your favorite Japanese dishes.