Cook and drain tortellini as directed on package. 

In a bowl, combine oil, vinegar and mustard. Pour the dressing over the cooked tortellini and toss to coat. (You can cool the tortellini in the refrigerator at this point and keep to use them later in the day.)

Mix lettuce, basil, tomatoes and pepper together in a large bowl.

Stir in the tortellinis (if they are still warm at this point, let mixture cool in the refrigerator for at least 1 hour).