Chicken and Pineapple Over Cous Cous

My mom and I took a cooking class last week titled "Casual Weekend Cooking" and this recipe was one that was featured that evening.  I've posted recipes before that I have learned while taking cooking classes.  I love that they share the recipes as a general guide and even the chef varies from what is written.  I varied the recipe today as well.  I pre-chopped the veggies and poached the chicken breast in advance and popped them in the fridge so that I could just throw everything together quickly when it was time for dinner.  That ended up coming in handy, because after taking a 12 mile bike ride, I didn't feel like cooking much!

1 Chicken Breast, poached and cut into small cubes
1 tablespoon Cornstarch
2 tablespoons Vegetable Oil
2 tablespoons Soy Sauce
1 1/4 cups Chicken Broth (or Pineapple Juice) (I used vegetable broth)
1 tablespoon Rice Vinegar
1/2 teaspoon Dry Mustard
1 tablespoon Fresh Ginger, grated
1 Garlic Clove, minced
1 bunch Scallions, white part minced and green part sliced thin for garnish
1 Onion, chopped
1 Green Pepper, sliced
2 cups Pineapple, cubed
2 teaspoons Sesame Oil

In a small bowl, stir together broth, soy sauce, vinegar, cornstarch, and mustard.  Put the vegetable oil into a wok and stir fry the ginger, garlic, and the white part of the scallions over moderately high heat for about 30 seconds.  Add the onion, green pepper, and salt and pepper to taste.  Stir-fry for about 2 minutes.  Add pineapple.  Stir the cornstarch mixture and add it to the wok.  Simmer the mixture, covered, for about 2 minutes.  Add the chicken and cook over moderate heat, stirring until heated through.  Stir in sesame oil.  Serve chicken mixture over cous cous and garnish with sliced scallion greens.