Preparation Puree first 4 ingredients in processor, scraping down sides of work bowl occasionally. Add yolks; puree 15 seconds longer. Strain through sieve set over large metal bowl, pressing on solids with back of spatula to release as much puree as possible. Discard solids in sieve. Set metal bowl over saucepan of simmering water (do not allow bottom of bowl to touch water); whisk puree until thickened and thermometer registers 170°F., about 10 minutes. Remove from over water. Whisk in butter 1 piece at a time. Cover and refrigerate overnight.
Preparation Puree first 4 ingredients in processor, scraping down sides of work bowl occasionally. Add yolks; puree 15 seconds longer. Strain through sieve set over large metal bowl, pressing on solids with back of spatula to release as much puree as possible. Discard solids in sieve. Set metal bowl over saucepan of simmering water (do not allow bottom of bowl to touch water); whisk puree until thickened and thermometer registers 170°F., about 10 minutes. Remove from over water. Whisk in butter 1 piece at a time. Cover and refrigerate overnight.