Remove the tops and bottoms of the onions, then slice in half and remove the skins, setting the skins aside for later. Finely slice all the onions along the grain (this will help keep their shape later), then peel and slice the garlic.

Add the butter, vegetable oil, onions, garlic and 1 tsp salt to a lidded medium-sized pot set over a high heat. Stir until all the butter has melted. Add a lid and reduce the heat to low. Leave to steam for 20 mins, checking and stirring after 10 mins to ensure no burning.

Meanwhile, combine all the stock ingredients plus a pinch of salt in a large jug. Set aside. Cook the noodles following pack instructions, then drain and rinse in cold water. Set aside.

Once the onions have been cooking for 20 mins, pour in the wine and increase the heat to high. Cook for 5 mins, stirring occasionally, until all the liquid has evaporated and the onions have slightly darkened and caramelised. Add all the stock mixture and thyme, then stir well. Lay the reserved onion skins on top of the ramen, put a lid on and reduce the heat to low. Simmer for 10 mins.

Remove the onion skins from the pot and discard. Add 2 tbsp grated cheddar and 2 tbsp lemon juice to the ramen, then mix well. Ladle the onion soup into two serving bowls, then divide the noodles between the bowls, letting them sit on the surface of the soup. Grate over a nest of cheddar cheese, top with the chilled diced raw onions, then carefully add 1 raw egg yolk per person. Finish with toasted sesame seeds, toasted sesame oil and, most importantly, a square of chilled butter.