Bombay Onions Stuffed with Kidneys

Ingredients

• 4 whole large Bombay onions (Large mild onions; Spanish or white onions are a suitable substitute if Bombay onions are unavailable.)
• 8 whole sheep's kidneys (Scalded and skinned but left uncooked at this stage. To scald: place kidneys in a bowl, pour over boiling water, leave 1 minute, drain, then peel away the thin outer membrane.)
• 2 whole anchovies (Spines (bones) removed and flesh cut into small squares.)
• 1 small handful fresh parsley (Finely minced. Have ready before stuffing.)
• 1 whole lime (Used for its juice; squeeze a drop or two over the filling as you pack each onion.)
• 1 portion (reserved from hollowing the onions) scooped-out onion interior (Finely mince the flesh removed when hollowing the onions, then season with pepper.)
• 4 small lumps (roughly 1 teaspoon each) butter (lump, for inside each onion) (One lump placed at the base of each hollowed onion before filling.)
• 4 small pats (roughly 1 teaspoon each) butter (pat, for topping each onion) (One pat placed on top of the filling of each onion before the cap is replaced.)
• 1 few drops lime juice (Squeezed from the lime listed above; applied during packing of each onion.)
• 1 light dusting spiced pepper (Applied occasionally during packing. Spiced pepper is a seasoned ground pepper blend; use black pepper with a pinch of ground spice such as clove or mace if a pre-blended version is unavailable.)
• 1 small knob butter (for greasing the baking dish) (Used to butter the baking dish before placing the stuffed onions inside.)
• 1 portion (separately made) brown sauce (A separately prepared savoury brown sauce; prepare this in advance or while the onions bake.)

Instructions

1. 1Prepare the eight sheep's kidneys: place them in a heatproof bowl and pour boiling water over them. Leave for 1 minute, then drain. Once cool enough to handle, peel away the thin outer membrane (skin) from each kidney. Set aside — they remain uncooked at this point.
2. 2Place the four large Bombay onions (skins left on or removed — leave skins on to help them hold their shape) into a large pot of boiling water. Boil until three-quarters cooked — they should feel slightly tender when pierced with a skewer but not completely soft. This will take approximately 20 minutes depending on size. Remove the onions from the water and drain them thoroughly. Set aside to cool enough to handle safely.
3. 3Using a sharp knife, slice off the top of each onion (about the top quarter) as you would slice the top off a boiled egg — this becomes the 'cap'. Carefully scoop out the inside of each onion using a small spoon, leaving a thick enough shell to hold the filling without collapsing. The hollow should be large enough to comfortably hold two small kidneys cut into eight pieces each. Reserve all the scooped-out onion flesh for the next step.
4. 4Finely mince the reserved onion flesh and season it well with pepper; set aside. Finely mince the fresh parsley; set aside. Take the two anchovies, carefully pick out and discard their spine bones, then cut the anchovy flesh into small squares; set aside. Cut each of the eight skinned kidneys into eight pieces (bite-sized chunks); set aside. Squeeze the lime and have the juice ready. Ensure the lump of butter, the pat of butter, the lime juice, and the spiced pepper are all within easy reach before you begin stuffing.
5. 5Preheat your oven to a slow/low temperature — approximately 150–160°C (300–320°F) or Gas Mark 2–3. A slow oven ensures the onions finish cooking gently and the kidneys cook through without becoming tough.
6. 6Butter a baking dish large enough to hold all four onions snugly. Now stuff each onion in the following order: First, drop a small lump of butter into the base of the hollow. Then add a little of the minced peppered onion. Next, place in the kidney pieces, tucking small squares of anchovy here and there among the kidney. Squeeze a drop or two of lime juice over the filling as you go. Dust lightly with spiced pepper. Crown the top of the filling with a little more minced peppered onion, then place a small pat of butter on top. Finally, place the onion cap back on top. Repeat for all four onions. Place the stuffed onions upright in the buttered baking dish.
7. 7Place the baking dish in the preheated slow oven. Bake for one hour. The onions should be completely tender and the kidneys cooked through by the end of this time. Do not rush this step with a hotter oven — the slow bake ensures the onions soften fully and the filling cooks gently.
8. 8Once the onions are done, remove the baking dish from the oven. Pour the separately prepared brown sauce over the stuffed onions. Serve immediately in their own baking dish.