Bring a kettle of water to a boil. Rinse the rice under the running tab, then add it to a bowl and cover generously with the boiling water. Leave to soak for 20 minutes, then drain and set aside.

Meanwhile, continue with the onions. Add around 2l of water to a pan large enough to also fit the onions. Cut the lemon in half and add it to the pan, squeezing some of the juice into the water. Bring to a boil. Meanwhile, trim the top and bottom 1 cm of the onions and peel them. Then use your knife to make a vertical incision, from top to bottom, up to the core of each onion, which will make it easier to remove the layers later on. Add the onions to the water, return to a boil, then reduce the heat and simmer for 15 minutes or until the onions have softened slightly. Fill a large bowl with cold water. When the onions are ready, use a slotted spoon to transfer them to the cold water.

While the onions are simmering, prepare the filling. Trim and discard the lower stems of the parsley and finely chop the rest, setting some aside in the fridge as a garnish later on; peel and finely grate or crush the garlic. Add everything to a large bowl along with the remaining ingredients. You don’t need to mix it yet.

Pre-heat the oven to 200 °C (392 °F) (180 °C (356 °F)). Once the onions are cold enough to handle, remove the individual layers, keeping them in tact as much as possible and discarding the thin membrane that will be left on top of the next layer. You’ll end up with the cores of the onions. Finely dice 3-4 of them, add them to the stuffing along with the drained rice and use your hands to mix it well. Either keep the remaining onion cores for other dishes or discard.

To stuff the onions, place 1 heaped tablespoon of the filling on the inner end of an onion layer and roll it up towards the other end, giving it the shape of a shallot. Transfer the stuffed onions to a wide, shallow casserole (around Ø 30cm), or a large roasting tray, as you go to create one snuck layer.

To make the sauce, whisk together the ingredients in a jug or bowl and pour it over the onions. Cut a parchment paper into the size of the casserole, moisten it by crumbling it under the running sink and use it to cover the onions. Roast them for 30 minutes, then remove the paper and roast for 20-30 minutes more or until they have absorbed most of the liquid and are beautifully golden. Remove from the oven and allow to sit for 10 minutes, during which the sauce will thicken further.

Traditionally, they are served at room temperature, but you can also enjoy them warm if you like. Serve with any of the remaining cooking liquid from the bottom of the tray and sprinkle with the reserved parsley.