Preheat the oven to 180°C.
Slice the lemon. Very thinly slice the beetroots (if the beetroots are organic, don’t peel them).
Mix the olive oil and white wine. You can add the garlic and a couple of pinches of chilli flakes if you’d prefer the dish a bit more tangy.
Add a layer of beetroot to a deep baking dish and brush them with the mixture. Scatter some dill on top and season with salt and pepper. Add half of the lemon slices, then put the fish on top. Season with salt & pepper then brush with the oil mixture and scatter more dill on top.
Put the remaining lemon slices on top of the fish then cover with a layer of beetroot. Pour over the remaining oil mixture, then season with salt and pepper.
Cover the dish with foil and bake for 20-25 minutes. Remove the foil and check that the fish and beetroots are cooked through. If not, put the dish back in the oven for a further 5 minutes, uncovered.
Serve warm.