Recipe Amish Slaw

Ingredients
1 medium head cabbage, cored and shredded
1 medium onion, finely chopped
1 cup white sugar
1 cup vinegar
1 teaspoon salt
1 teaspoon celery seed
1 teaspoon white sugar
1 teaspoon prepared mustard
3/4 cup vegetable oil

Directions
In a large bowl, toss together the cabbage, onion, and 1 cup sugar. In a small saucepan, combine the vinegar, salt, celery seed, 1 teaspoon white sugar, mustard and oil. Bring to a boil, and cook for 3 minutes. Cool completely, then pour over cabbage mixture, and toss to coat. Refrigerate overnight for best flavor.