Preheat oven to 180°C. Wash and trim beetroot. Wrap each one seperately in aluminium foil with a drizzle of EVOO and place into a baking tray. Roast until tender. Cool until you can touch them.
Using the foil, rub the skins off and discard. Quarter or cut each beetroot into wedges and place into a shallow dish.
While the beetroot is roasting, dry toast the coriander seeds on a medium heat until fragrant and just smoking. Cool.
Place all remaining ingredients into a bowl with the toasted coriander seeds and stir with a fork. Pour over the still warm beetroot. Allow to marinate for at least 1 hour.
Serve on their own, or as shown, with fresh baguette, bocconcini and plenty of EVOO.