It's dinner time!

Ingredients

• 2 cups mayonnaise
• ⅓ cup prepared horseradish
• 2 teaspoons dry mustard powder
• 2 teaspoons lemon juice
• 1 teaspoon seasoned salt
• ½ teaspoon salt
• 1 (8 ounce) package rigatoni pasta
• 1 pint cherry tomatoes
• 1 (15 ounce) can jumbo pitted black olives, drained
• 1 (8 ounce) can whole water chestnuts, drained
• ½ head cauliflower, broken into florets
• 1 zucchini, cut into strips
• 1 green bell pepper, cut into thin strips
• ½ pound small whole fresh mushrooms
• 1 ½ pounds cooked shrimp, peeled and deveined