You will need:
1 head cauliflower, cut into bite sized pieces
1 head broccoli, cut into bite sized pieces
1 onion, chopped
1 cup mayonnaise or salad dressing
1/4 cup wine vinegar
1/2 cup vegetable oil
Mix dressing together in glass measuring cup.
Pour over bowl full of prepared vegetables.
Toss to coat.
Refrigerate a few hours to allow flavors to mingle. Serves 6 or more.