Make sure your coal embers are nice and hot or alternatively if it buckets down with rain, you can roast in the oven at 180˚C.
Take 2 sheets of tin foil approximately A4 size. On one sheet place the beetroot with the thyme and two of the tablespoons of olive oil. On the other piece place the shallots and pour on the third tablespoon of olive oil, honey and garlic. Pinch both sheets to form two parcels and roast for 30 minutes.
Take another piece of slightly bigger foil, pour on one tablespoon of olive oil and place the fillets of hake on top. Pour the lemon zest and juice over the top and finally a scattering of garlic. Pinch to form a parcel.
Once the beets and shallots are cooled and you are ready to serve – roast off the hake parcel for 6 minutes.
Whilst the hake is cooking make the pea dressing (This can be made in advance although it will discolour slightly). Blend the peas in a food blender with the vinegar, oil, spinach, sugar, salt and pepper.
When ready to serve up, arrange the potatoes, beetroot and shallots on the plate, spoon around the pea dressing and finally put the fish on top, pouring over any of the cooking juices.