Snap off tough ends of asparagus. Cover and cook in a small amount of boiling water 5 minutes or until crisp-tender. Drain and rinse under cold running water; drain well.
Trim white portion from green onions, and reserve for another use. Place green onion tops in a bowl; add boiling water to cover. Drain immediately, and rinse under cold running water.
Gather asparagus into 10 bundles, and add 2 bell pepper strips to each bundle. Tie each bundle with a green onion strip. Place bundles in a 13 x 9-inch baking dish.
Combine chopped onion and next 9 ingredients (onion through pepper) in a bowl; stir well. Pour over asparagus bundles. Cover and chill 2 to 8 hours.
To serve, remove asparagus bundles from marinade, and discard marinade. Arrange asparagus bundles on a serving platter.