1 large sized celeriac (also known as celery root, this can be substituted with parsnips or white turnips)
1 white onion, roughly diced
1/2 cup (100g) of unsalted butter
3 fresh bay leaves
A sprig of thyme
6 & 3/4 cups of liquid stock vegetable, chicken or veal
3 & 1/2 cups (800ml) of milk
1 head of fennel
4 eggs - (1 egg per individual serving)
1 tbsp (20ml) Olive oil
salt to taste
black pepper to taste
1. Place a saucepan on a medium heat and add the butter. When the butter has melted add the onion and let them sweat, keep an eye to make sure they do not color.
2. Clean up the celeriac by trimming off all the edges with a sharp knife, removing any knobbly bits. Evenly dice into 2cm (0.78 inch) pieces and add to the pan with the bay leaves and thyme.
3. Cover the celeriac by pouring in the stock and milk in. Season with a good pinch of salt and a couple of turns of pepper. Gently simmer on a medium to low heat for 20 to 30 minutes, until the celeriac is tender.
4. The celeriac is ready when you can pierce it with a knife easily. Using a mandolin, or sharp knife, finely slice the fennel. Grease a small bowl with a little olive oil and separate 4 egg yolks into the bowl, making sure to keep the yolks intact.
5. Add these when the soup is ready for a rich, luxurious flavor. When the celeriac is tender, use a slotted spoon to transfer the celeriac into a blender. Reserve the juices in case you want to make the soup thinner. Blend the soup until smooth, if the soup is too thick add some of the juices and pulse further. Season further to taste.
6. Serve in deep bowls and garnish with the fennel and an egg yolk each. Season the yolk with a pinch of salt and a turn of pepper.