Saffron Mayonnaise

Directions

1. 1
   Process the egg, mustard, and 1/4 teaspoon salt in a food processor until pale and foamy, about 1 1/2 minutes.
2. 2
   Combine the oils; with the machine running, add the oil, drop by drop, through the feed tube until the mixture begins to thicken (about 1/4 cup oil; do not stop the machine).
3. 3
   Add the remaining oil in a slow, steady stream, processing until incorporated.
4. 4
   Gradually add 1 tablespoon of the lemon juice.
5. 5
   Grind the saffron with a mortar and pestle.
6. 6
   Transfer to a bowl.
7. 7
   Add the remaining teaspoon lemon juice; let stand until the liquid turns yellow, 5 minutes.
8. 8
   Strain; discard the saffron threads.
9. 9
   Put the mayonnaise into a small bowl; drizzle in the saffron liquid, stirring.
10. 10
    Season with salt, if desired.
11. 11
    Cover; refrigerate until ready to serve, or overnight.