This is pretty much a standard issue vinegar cole slaw. 

Combine the following in a non-aluminum saucepan:

• 1/2 cup white vinegar
• 6 tablespoons sugar
• 6 tablespoons vegetable or canola oil
• 2 1/2 teaspoons dry mustard
• 1 teaspoon celery seed

Stir over medium heat until sugar dissolves and dressing comes to a boil. Remove from heat. Some may want to add a dash of salt, but I usually just a dash of pepper.

Combine the following in a large bowl:

• 1 medium cabbage that has been thinly sliced
• 1 large white onion, thinly sliced
• 1 large green bell pepper, thinly sliced 

 Add dressing and toss to coat.  Cover and refrigerate at least 2 hours, but I prefer to make this a day ahead before needed.