Italian Deli-Style Cole Slaw

1 large head cabbage
3 to 4 sliced, large onions
1 cup sugar (Splenda can be substituted)
3/4 cup oil
1 teasp. dry mustard
1 cup vinegar
2 teasp. salt
1 teasp. celery seed.

In a large bowl, alternate layers of thinly shredded cabbage with thinly sliced onions. Pour 1 cup of sugar over mixture and set aside. Make a heated sauce by mixing and bringing vinegar, oil, salt, mustard, and celery seed to a boil. Pour over cabbage and onion mixture and let stand covered at room temperature for 4 to 6 hours. Mix well before serving.