To make the dressing, whisk together the oil, vinegar, salt, sugar, pepper and mustard until emulsified. Stir in the fresh herbs.Combine the vegetables, kidney beans, corn, and cheese in a large mixing bowl.Pour the dressing over the salad, cover, and refrigerate at least 3 hours (the longer the better) before serving. Let stand at room temperature at least 30 minutes before serving. Enjoy with some crusty bread.