Lamb Liver Soup with Egg-Lemon Tempering

Lift the thin, shiny membrane on the liver with the tip of a knife and pull it off by hand; if left on, it will shrink during cooking and make the piece too tough to eat with a spoon. Cut away the white connective tissue and dice the liver into 1.5 cm cubes. Rinse under cold running water until the water runs clear, drain in a colander, then pat dry with paper towels.

Melt the butter in a pot over medium heat. Add the finely chopped onion and cook, stirring, until translucent and noticeably reduced in volume, without letting it brown. Add the flour and stir constantly until its raw smell is gone and it turns pale hazelnut-brown. If you rush this step, the soup will taste floury.

Add the water gradually, whisking after each addition to prevent lumps. Add the salt and black pepper and bring to a boil. Reduce the heat and simmer for 15 minutes, until only an occasional bubble breaks the surface. The soup is ready when it coats the back of a spoon in a thin layer.

Heat a large skillet until very hot. Add the liver cubes in a single layer with space between them. If crowded, they will release liquid and steam instead of searing. Turn them for 2–3 minutes, until browned on all sides, then remove them while still pink inside; they will continue cooking in the soup.

Whisk the egg yolks and lemon juice in a bowl. Gradually whisk in a ladleful of soup in a thin stream, continuing to whisk after each addition. Repeat 3–4 times, until the bottom of the bowl feels warm. Pour the mixture into the pot while stirring, then heat the soup until steaming without bringing it back to a boil.

Stir the seared liver into the soup and cook for 2 more minutes. In a small skillet, heat the remaining butter until foamy, then remove it from the heat. Stir the dried mint and red pepper flakes into the hot butter; the mint begins to darken as soon as it hits the oil, so the heat should be off. Drizzle the butter over the soup and serve hot.