1 package (7.75 ounces) Suddenly Salad® Classic Pasta Salad mix
1/4 cup mayonnaise or salad dressing
3 tablespoons cold water
2 packages (2 1/2 ounces each) sliced pastrami, cut into 1/2-inch strips
1 can (4 ounces) mushroom stems and pieces, drained
1 medium tomato, cut into 1/2-inch pieces