1 sm. head cauliflower, broken into flowerettes
1 lb. broccoli, broken into flowerettes
1/2 lb. fresh mushrooms, sliced
1 sm. purple onion, sliced and separated into rings
2 stalks celery, sliced
1 c. vegetable oil
1/2 c. white wine vinegar
1/2 c. sugar
1 tbsp. Italian seasoning
2 tsp. dry mustard
1 tsp. salt
Lettuce leaves (optional)

Combine first 5 ingredients in a large bowl; set aside. Combine oil and next 5 ingredients; stir well, and pour over vegetables. Toss gently to coat; cover and chill 3 hours or overnight, stirring occasionally. Serve with a slotted spoon over lettuce, if desired. 10 to 12 servings.