Instructions
Follow the steps and taste along the way.
Cook the vegetables for the purée
Cut the celeriac and potatoes into pieces about 2 cm in size. Place them in a pot, cover with 1 l of water, add 2 g of salt, and cook for 16–18 minutes, until easily pierced with a fork. Drain, reserving 100 ml of the cooking water, and mash the vegetables with 8 ml of olive oil. Add a little of the reserved water as needed to make the purée smooth but not runny.
Cook the green beans
In a second pot, bring 600 ml of water and 1 g of salt to a boil. Cook the green beans for 4–5 minutes, until tender but still firm and green. Drain and set aside.
Sear the pork medallions
Cut the pork loin across the grain into four medallions of roughly equal thickness and pat them dry. Season with the remaining 1 g of salt and the pepper. Heat 8 ml of oil in a pan; sear the meat over medium-high heat for 3–4 minutes per side, until a golden-brown crust forms. The thickest piece should reach 63 °C in the center. Transfer the meat to a plate and let it rest for 3 minutes.
Make the apple-mustard pan sauce
Add the remaining 4 ml of oil, finely chopped shallot, and diced apple to the same pan. Cook for 3 minutes, stirring occasionally, until the shallot softens and the edges of the apple are lightly colored. Pour in the stock and add the chopped sage and mustard. Cook for 2–3 minutes, until the sauce thickens slightly, then stir in the lemon juice. Return the meat and any juices from the plate to the pan and briefly coat them in the sauce.
Finish the beans and serve
In a clean pan or pot, warm the green beans for 1 minute with a tablespoon of water. Divide the purée and beans between two plates, add the medallions, and spoon over the apple-mustard pan sauce. Serve immediately, while the meat is warm and the beans are still firm.
