Chop up the onions, peppers and zucchini into bite sized pieces. Thread on the skewers alternately with the chicken pieces.
1 red pepper, 1 onion, 1 zucchini
Brush some sauce on the meat and vegetables on the skewers.
Put the kebobs in the oven to bake for about 10 minutes, flipping once.
While the kebobs bake, bring the sauce to a boil in a small saucepan. Then reduce the heat, and take about 2T of the sauce out of the pan. Combine it with the cornstarch, and stir it back into the saucepan.
1 Tablespoon cornstarch
Continue to stir the sauce on low heat until it thickens.
After the kebobs are baked 10 minutes, turn the oven to broil, and broil the skewers for 4 minutes, turning once, to brown them.