Heat the oil and butter in a heavy based pan, when melted add the onion and cook, stirring until softened.

Add the marrow and potato and sweat for 5 minutes, stirring occasionally.

Meanwhile, dissolve the vegetable stock cube and the chicken stock cube in 12 fl oz of boiling water. Add this to the pan.

Add the milk and bring to the boil, stirring continuously.

Add salt and pepper to taste.

Turn down heat and simmer for 20 minutes.

Remove from heat and blend with a hand blender until desired consistency.

Spoon into dishes and sprinkle with parsley sprigs.

Croutons -

Grease a non stick baking tray with the butter.

In a dish combine the oil and chilli flakes, add the cubed bread and stir, scatter on the greased baking sheet and cook in oven at 200 C for 10-15 mins until crispy. Immediately sprinkle with the grated cheese and serve with the soup.