Combine sauce velouté, stock, and 1 c. of heavy cream in a large saucepan.
2
Bring to a boil over high heat and reduce to a nappé consistency. Be sure to skim any scum while the sauce is reducing. Stir periodically so that the sauce does not burn.
3
Add remaining cream and bring just to a boil.
4
Remove sauce from heat, add butter and stir with a whisk.
5
Strain through a chinois.
6
**Hold at or above 135°F (57°C) or cool below 70°F (21°C) in two hours or less, and below 41°F (5°C) in less than a total of six hours.