1. Divide the cauliflower in flowerets. Cook in boiling water until tender and crisp. Drain under running cold water and set aside.
2. Cook the carrots in boiling water until tender and crisp. Drain under running cold water and set aside.
3. In a bowl place the cauliflower and carrot. In another bowl mix oil, vinegar, orange zest and juice, basil, pepper and salt. Pour over the vegetables; mix gently and add the scallions. Cover and marinate 2-3 hours.