Trim the duck breast filets by removing the nerve with a fork or filleting knife. Rinse and pat dry.
Dissolve cornstarch in water and set aside. Put the rest of the sauce ingredients in a saucepan and bring to a boil. Reduce heat, add the cornstarch and simmer for 1 minute. Set it aside.
In a wok over medium-high heat, heat the olive oil and then add the filets. Cook for 1 minute on each side, turning with a spatula (do not prick the meat with a fork). Remove from the wok and set aside.
Sauté the vegetables and garlic (except the chestnuts) for 6 to 8 minutes, adding a little olive oil if necessary to keep them crisp. Add the water chestnuts for the final 2 minutes of cooking. Add the fillets and sauce and mix well.
Serve over basmati rice.
Recipe from Mr Jean Tremblay, a duck passionate