1. Cook pasta, uncovered, in 3 to 4 quarts boiling water until tender to bite, about 12 minutes. Drain, then rinse with cold water until cool; drain well.
2. While pasta cooks, chop the green onions and Roma tomatoes. Stem, seed, and mince jalapeños. Stem, seed, and cut the bell pepper into thin, short slivers.
3. In a large bowl, combine the pasta, onions, tomatoes, jalapeños, bell pepper, cilantro, and beans. Add the vinegar, oil, and cheese; mix well. Transfer to a serving platter. If desired, add salt to taste.