1.Mix Cornstarch, Broth, Soy, Sugar, Garlic Powder And Ginger In Saucepan. Cook And Stir Until Mixture Boils And Thickens. 2.Thread Alternately Pork, Mushrooms And Onion On 4 Skewers. 3.Grill Or Broil Kabobs 20 Minutes Or Until Done, Turning And Brushing Often With Broth Mixture. Thread 1 Tomato On Each Skewer. 4.Heat Remaining Broth Mixture To A Boil. Serve With Kabobs And Rice.