In a large bowl, toss together the cauliflower, mushrooms, chickpeas, radishes, chilies and ¾ teaspoon salt; let stand for about 10 minutes. Meanwhile, in a small bowl, stir together the yogurt, oil, lemon juice, honey, garlic and ¼ teaspoon each salt and pepper.
Add the yogurt mixture and half the dill to the vegetables and toss. Taste and season with salt and pepper. Let stand for about 30 minutes. Transfer to a platter and sprinkle with the remaining dill.
