Stir-Fried Beef and Chinese Vegetables

2 Tbsp dry red wine
1 Tbsp soy sauce
1/2 tsp sugar
1 1/2 tsp gingerroot, peeled, grated
1 lb boneless round steak, fat trimmed, cut across grain into 1 1/2-inch strips
2 Tbsp vegetable oil
2 medium onions, each cut into 8 wedges
1/2 lb fresh mushrooms, rinsed, trimmed, sliced
2 stalks (1/2 C) celery, bias cut into 1/4-inch slices
2 small green peppers, cut into thin lengthwise strips
1 C water chestnuts, drained, sliced
2 Tbsp cornstarch
1/4 C water