Halve the carrots lengthways, then separate and bash the garlic cloves, leaving their skins on.
Place on a large baking tray. Lightly crush and add the coriander seeds, and drizzle over the vinegar and oil. Toss the carrots and garlic to coat, then season with sea salt and black pepper.
Roast in the oven for 45 minutes, or until the carrots are tender and caramelised in places but still have some bite. Remove the garlic as it caramelises or if it looks like it’s burning.
Squeeze the garlic flesh from the skins and mash well. Mix through the yoghurt then serve in a bowl next to the roasted carrots.