Grilled mackerel, beetroot in horseradish and leftover root veg bake

The only part of this which is a "recipe" is the beetroot in horseradish.  The root veg are yesterdays leftovers heated through, and the mackerel is grilled on a hot grill - skin side first, with a little olive oil on the fish.  My grill was not hot enough - it needs to get really hot.  I also braised some celery - in the oven, with olive oil and white wine - covered with foil.


Beetroot
olive oil
garlic
natural yogurt
horseradish

1.  Put beetroot, washed and whole in a baking tray, add splosh of olive oil and a small handful of garlic cloves.
2.  Cover with foil and roast for an hour or so.
3.  Peel and chop the roast beetroot, squeeze on the roast garlic, leave to cool slightly.
4.  Mix together 3 spoons of natural yogurt and 1 spoon of horseradish.  Stir into the slightly cooled beetroot.