Serves 6

Peel the celeriac and potato and chop both into 1-inch cubes. Put them in a medium saucepan and add enough water to cover. Add a pinch of salt. Bring to a boil and cook for about 15 minutes or until the celeriac is easily pierced with a fork. Remove the saucepan from the heat, drain, and return the potatoes and celeriac to the warm saucepan. Add the butter, milk, cheese, salt and pepper and mash until well combined. For an extra smooth mash, use an immersion blender or food processor.

Heat olive oil in a large skillet over medium heat. Add the ground meat and cook until no pink remains. Add carrots, celery and onion and cook until softened, 5 to 7 minutes. Add garlic, tomato paste, flour, salt, thyme and parsley. Cook for 2 more minutes, stirring constantly. Add the wine, scraping the bottom of the pan, and cook for a few minutes until the wine reduces slightly. Stir in the broth and Worcestershire sauce. Reduce heat to low and simmer until thickened, 20 to 25 minutes.

Preheat the oven to 400°. Let the skillet mixture cool slightly while the oven preheats. Put the skillet on a rimmed baking sheet lined with foil to catch any overflow. Carefully spoon the celeriac mash on top of the filling, starting with the outer edges and making sure to press the mash along the edge of the pan. Smooth out the mash, creating a few deep ridges with the back of a spoon. Bake for 20 minutes, then broil for 5 more to brown the top slightly. Let rest 5 to 10 minutes. Top with chopped parsley just before serving.

Vegetarian

Replace the meat with ½ cup dry French green lentils and 8 ounces sliced mushrooms. Replace the beef broth with vegetable broth. Instead of browning the meat, sauté the mushrooms in oil until they have released their liquid and are slightly browned. Add lentils with the broth. If the lentils are not cooked after 25 minutes and the pan is dry, add splashes of water and continue to simmer until they are fully cooked. Continue with the recipe as written.