Fry sliced apples in 25g butter for five minutes until lightly browned and set aside.
Gently fry onions, celeriac, and carrot in remaining butter and oil for 15 minutes.
Stir in garlic, apples, potatoes, thyme, and bay leaf for three minutes.
Add 1.3l stock and pepper, bring to a boil, then simmer for 25 minutes.
Discard herbs and blend the soup until smooth, adding water if needed for consistency.
Season with salt and pepper to taste and set aside.
Fry bacon in orchid oil until crisp, then drain on paper towels.
Mix crème fraîche with milk in a small bowl until smooth.
Reheat soup gently and ladle into warmed bowls.
Top with crème fraîche mixture, bacon pieces, and fresh parsley to serve.