Heat a dash of olive oil in a medium saucepan, then add the onion and fry for a few minutes, or until softened.

Meanwhile, put the quartered Brussels sprouts into a pan of boiling water and boil for 2-3 minutes, before draining well.

Add the sprouts and the garlic to the onions and fry for 1-2 minutes. Add the stock and cream and simmer for 3-4 minutes.

Use a stick blender to puree the mixture until smooth. Return to the heat and stir in the cheese and season to taste.