Melt butter in a frying pan over medium heat. Add onion. Cook, stirring, for 5 minutes or until softened. Add garlic and mushrooms. Cook, stirring, for 3 to 4 minutes or until softened.

Add wine. Bring to the boil. Reduce heat to medium-low. Simmer for 2 to 3 minutes. Stir in cream. Bring to the boil. Simmer for 10 minutes or until reduced by half. Season with salt and pepper.