6. Add the garlic and cook it for about 1 minute.
7. Stir in the wine, raise the heat slightly & bring to a simmer. Simmer for about 5 minutes, until reduced by about half.
8. Sprinkle in the flour, a bit at a time, stirring between each addition to form a paste that coats the onions.
9. Pour in the milk, a bit at a time, whisking between each addition.