Avgolemono (?) Greek lemon-egg soup...or Sauce

Hmmm...not sure how enthusiastic I am about lemon-egg soup. But...slightly thicker, as a sauce...it was good over broccoli! But I saw a avgolemono soup recipe presented as a sauce in a magazine (Cooking Light, if I remember correctly, but it was years ago), so I found a recipe, reduced it (I don't need a ton of it, used as a sauce), thickened it a bit and...here you go!

Ingredients
2/3 C chicken stock
1 egg
2 tsp lemon zest
2½ tsp lemon juice
pinch salt
1 tsp extra virgin olive oil

Directions
Heat the chicken stock in a saucepan to just simmering. Meanwhile, whisk together everything else except the olive oil until very light and frothy. Whisk, whisk, whisk!

Temper the egg mixture by slowly adding a little of the hot chicken broth at a time while continuing to whisk. Add about half the chicken broth this way, then slowly add the tempered egg mixture back into the saucepan, whisking continuously.

Reheat the mixture just until it thickens (don't boil it!). Remove from heat and whisk in the olive oil.