I just made this at lunch today and it was performed quite well on a BLT sandwich. No oil to whip and fewer calories. Once cold, it has that mayo texture. Nice and tart.
- Melt the butter in a skillet and stir in the flour.
- Add the milk all at once and stir over medium heat until thick.
- Remove from heat and beat in the egg yolk., lemon juice, mustard and salt.
- Stir in the yogurt and cool.