Thai Sweet and Sour Chicken

When Chuck and I started eating at Thai restaurants, Chuck always ordered sweet & sour chicken.  This has been a hard recipe for me to duplicate for some reason but I finally feel like I'm getting it right.

Recipe:

1/3 C oil

1 Tbs garlic, coarsely chopped
1 lb chicken, thin-sliced on angle
3 Tbs flour for dusting chicken
1 small carrot, thin-sliced on angle
¼ C green onion, sliced
½ small onion, wedged
½ small bell pepper, chunks
¾ C fresh or canned pineapple chunks
½ C cucumber chunks, unpeeled
½ C cocktail tomato wedges

Sauce:

¼ C pineapple juice
2 Tbs chicken broth
4 Tbs or more palm sugar to taste
2 Tbs rice vinegar
2-2½ Tbs fish sauce
2 Tbs oyster sauce
1½ Tbs ketchup
1 1/2 tsp cornstarch
½ tsp chili paste or Thai chili (optional)

Mix sauce ingredients in saucepan. Bring to boil for one minute. Put flour and chicken in grocery bag and shake to coat all over. Heat wok on high until starting to smoke. Add oil, then chicken and stir-fry, adding garlic after a few seconds, until halfway done. Add carrots, onions and green pepper and stir-fry 1-2 minutes. Add sauce and continue to stir-fry about 15 seconds. Add pineapple and stir-fry about 20-30 seconds. Remove from heat and add tomatoes and cucumbers or serve them on the side. Serve with Jasmine rice.