I can confirm these are the best onions I have ever tasted. I don’t know how he’s done it as there are only three ingredients but he has! The first recipe I’v tried from @ottolenghi ‘Flavour’ book and I can tell you I’m obsessed.
✔️8 regular sized onions
✔️100g unsalted butter, melted
✔️100g white miso paste
Pre-heat the oven to 240° fan.
Half the onions lengthways, discarding the papery skin, as well as the layer beneath if it is tough or dry. Trim the tops, and a little of the bottom (not too much – you want to ensure the onion halves stay held together at the base).
Whisk the melted butter, miso and 1 litre of warm water together until fully combined.
Place the onion halves, cut side down and spaced apart, in a 40 cm x 28 cm high – sided baking tray or dish and pour over the miso water. Cover tightly with foil and bake for 35 minutes, then remove the foil and turn the onions over so they are cut side up. Baste the onions very well, then return to the oven, uncovered, for about 45–50 minutes, basting every 10 minutes, until the onions are very soft, deeply browned on top, and the sauce is reduced to a gravy consistency.
Carefully transfer the onions to a platter, pouring the sauce over and around them, and serve at once.