Cook beans, covered, in a small amount of boiling salted water 1 hour or until beans are tender. Drain; reserve 1 1/2 cups liquid.
Saute onion and green pepper in butter in a large skillet until tender. Add chili sauce, vinegar, mustard, horseradish, salt, curry powder, red pepper, and reserved cooking liquid. Cook over medium heat 5 minutes. Add beans; simmer 10 minutes.