Mix The Cumin, Chili Powder, Brown Sugar, Garlic Powder, Cornstarch And Salt In Medium Bowl. Add The Chicken Strips; Toss Until Coated. Heat The Oil In Large Nonstick Skillet Over Medium-High Heat. Add The Chicken To The Skillet. Cook And Stir For 5 To 7 Minutes Or Until No Longer Pink In The Center. Add The Onion And Pepper Mix; Cook For An Additional 3 To 5 Minutes Or Until Thoroughly Heated, Stirring Frequently. Meanwhile, Warm The Flour Tortillas As Directed On Package. For Each Taco, Spoon 1/4 Cup Chicken Mixture On One Half Of The Tortilla. Top A Dollop Of Sour Cream. Fold Over To Serve.