This makes a lot, great for a party.

Easy Overnight Vegetable Salad

1 large bunch or carrots
2 heads of cauliflower, separated into flowerettes
1 bunch of broccoli, separated into flowerettes
3 sweet purple onions, thinly sliced
2 cans pitted ripe olives, drained
1 pound or more small fresh mushrooms
5 bottles Italian dressing
few sprigs of fresh dill (optional)

1. Cook carrots, cauliflower and broccoli until barely tender.  Rinse in ice water to stop cooking.
2. Slice carrots into small thin strips. 
3. Combine all vegetables and dill and pour dressing over all.
4. Marinate in refrigerator overnight.
5. Drain and serve on lettuce in a large salad bowl.

Makes 30 to 40 servings.