Melt the butter in a large stockpot over medium-high heat. Add the onion and cook about 3 minutes. Stir in the garlic, celery, celeriac, carrots and cook for 2-3minutes. Add the mushrooms and cook until they become limp. Add marsala wine and cook until the wine completely evaporates.
Now add flour and cook for another minute. Add chicken stock and bring to a boil over high heat and then reduce the heat to maintain a simmer. Cook until the mushrooms are tender.
Remove from the heat and let cool slightly. Blend the soup with a stick blender. Return the mixture to the medium heat and stir in the creme fraiche. Add salt and pepper to taste, if needed, and let it simmer for 1-2minutes.
Meanwhile cut the bread slices into small cubes and put them in a bowl. Add olive oil, garlic, grated parmesan, salt, pepper, and chopped oregano. Mix everything and transfer to a baking tray. Bake in a preheated oven at 170C until golden brown.
Serve the soup with few croutons on top and fresh oregano.
Bon Appetite
