In a medium pan on low heat add butter and garlic until soft. Stir in wine and cook for a further minute. Add cream and pepper and cook for a further 1-2 minutes.
Dissolve cornflour in a little water and stir into the sauce to thicken, a little at a time, until desired consistency. Cook for 3-4 minutes until thickened and the cornflour has cooked out. Taste and adjust seasoning.