1. Preheat broiler.
2. Cut bell pepper in half lengthwise; discard seeds and membranes. Place pepper halves, skin sides up, on a foil-lined baking sheet; flatten with hand. Broil 15 minutes or until blackened. Place in a zip-top plastic bag; seal. Let stand 15 minutes. Peel and chop.
3. Bring 4 quarts water and 2 teaspoons salt to a boil in a large saucepan. Cook pasta according to package directions, omitting additional salt and fat. Drain and rinse with cold water; drain well.
4. Combine bell pepper, pasta, remaining 1/4 teaspoon salt, arugula, and remaining ingredients in a large bowl; toss well.