Next sauté onion cut into thin strips, celery cut diagonally, and water chestnuts sliced lengthwise in 2 Tbsp oil for 5 minutes. Remove and set aside.
In remaining oil sauté the dredged shrimp pieces. Keep stirring until brown on all sides (about 10 minutes).
Add the sautéed vegetables, 4 slices of pineapple cut into wedges plus pineapple juice mixed with sauce from dredging, and simmer until thoroughly heated.
Serve over bed of steamed rice