Soak the cauliflower 30 minutes, head down, in salted water to cover.
Break it up into separate flowerets and cook in boiling salted water 5-8 minutes.
They should still be crisp.
Combine the cooked and cooled cauliflower flowerets with the olives and peppers, toss with enough dressing to coat the pieces, and let marinate in the refrigerator several hours.
Toss lightly before serving.