Trim the Brussels sprouts, remove any wilted outer leaves, trim the stem slightly, and cut the sprouts in half (quarter large ones). Peel the garlic cloves and cut them into thin slices. Wash the organic lemon with hot water, finely grate some zest, and squeeze the juice from one half of the lemon.

Toast the walnut kernels in a dry pan without fat over medium heat for 3–4 minutes until golden brown and fragrant. Then remove, let cool briefly, and roughly chop.

Bring plenty of salted water to a boil in a large pot and cook the orecchiette according to the package instructions until al dente. Before draining, ladle out about 100 ml of the starchy pasta water and set aside.