Sweet and Sour Chicken

I made this recipe while we had extended family in town for Nephi's baptism last month. It was part of the Aussie/NZ recipe swap and my teammate was Peter J from Tasmania, Australia. This is one of his creations. I really like how thick the sauce is. I used my fake pineapple in place of the real deal and you really couldn't tell.

Sweet and Sour Chicken
2 chicken breasts, diced
2 tsp olive or vegetable oil
pepper and salt

Sauce: Part 1
1 medium onion, diced
2 tsp olive or vegetable oil
1/2 cup pineapple pieces
1/4 - 1/2 cup bell peppers, finely diced

Sauce: Part 2
1/4 cup brown sugar
1/4 cup ketchup
1/4 cup white OR cider vinegar ( I used rice vinegar)
1/4 cup pineapple juice
1/4 cup water
2 tsp cornstarch

In a small saucepan saute onion from Sauce: Part 1 in oil over medium-low heat until soft but not brown. Mix in pineapple and bell peppers and set aside. Rinse the saucepan, add Sauce: Part 2 ingredients and mix thoroughly. Bring to a gentle boil stirring constantly until sauce thickens slightly, remove from heat and stir in Sauce: Part 1 ingredients. This can be done in advance and refrigerated to allow flavors to "marry."
Season chicken with salt/pepper to taste. Cook chicken in oil over medium-high heat until cooked through. Meanwhile, gently warm up the sauce. Mix the chicken in thoroughly. Serve over hot cooked rice.