This one is from Eating Well, and I made zero changes. If you are craving Eggs Benedict and dont want all those extra calories – this is a great substitute. The sauce is also great on veggies.
1 TBSP butter
3/4 c nonfat buttermilk
1 TBSP cornstarch
1/2 tsp salt
Pinch of cayenne pepper
1 large egg, lightly beaten
1 TBSP lemon juice
Melt butter in a small saucepan over low heat. Cook, swirling the pan, until the butter turns golden, 30 to 60 seconds. Pour into a small bowl and set aside.
Whisk 1/4 cup buttermilk, cornstarch, salt and cayenne in a heavy medium saucepan until smooth. Whisk in egg along with the remaining 1/2 cup buttermilk.
Set the pan over medium-low heat and cook the sauce, whisking constantly, until it comes to a simmer. Cook, whisking, for 15 seconds.
Remove from heat and whisk in lemon juice and the reserved butter. Serve hot or warm.