Drain bean salad; reserve 1/2 cup liquid. Combine reserved liquid, pesto and salt, if desired; set aside.
Cook tortellini according to package directions; drain, rinse in cold water and drain again. Add pesto dressing; toss to coat. Add stir-ins if desired (see below). Toss with bean salad. Serve at room temperature or chilled.
Optional stir-ins: grape tomatoes or halved cherry tomatoes; chopped bell pepper; thinly-sliced green onion.