1. Cook the beetroot in boiling salted water for 20 minutes, or until just tender. Drain, return to the saucepan and cover with cold water. When cool enough to handle, drain well and slip off the skins.
2. Heat the oven to 180°C (gas mark 4). Season the duck breasts with sea salt and pepper. Heat a heavy frying pan (with an oven-proof handle) over a medium heat, then add the breasts (skin-side down) and sear for 2-3 minutes, or until golden. Turn the breasts over, transfer to the oven and cook for 12 minutes (for medium), or until cooked to your liking.
3. Put the asparagus and beetroot in a baking tray, brush with a little oil and place in the oven at the same time as the duck, and roast for 12-15 minutes. When the duck is cooked, set aside to rest for 5 minutes, then slice.
4. Make a dressing by combining the oil, orange juice, mustard, honey and garlic in a screw-top jar. Shake well and season to taste. In a large bowl combine the beetroot, asparagus, peas, baby gem and basil. Add some dressing, mix gently and divide between 4 large plates, then top with the duck slices.