Marinated Beet Salad

Drain beets reserving 1/4 cup liquid and slice into 1/4 to 1/2 inch slivers. Add onions and toss.

In a saucepan over medium heat cook the sugar mustard and reserved 1/4 cup liquid until dissolved. Add vinegar and bring to boil; remove from heat and allow to cool.

Pour over the beet slices and onions toss and refrigerate for 4 to 6 hours. Remove from refrigerator and serve at room temperature.