In A Bowl, Whisk 4 Tablespoons Oil, Vinegar, Sugar, Celery Seed And Salt Until Sugar Is Dissolved; Set Aside. In A Large Skillet, Saute The Cabbage, Carrots And Onions In Remaining Oil Until Crisp-Tender, About 15 Minutes. Stir In Vinegar-Oil Mixture And Corned Beef. Cover And Simmer For 10 Minutes Or Until Heated Through.