I did need to make a few changes because I didn't have all the ingredients. I had to use sour cream and regular mayo. For my own tastes, I added about a tsp. of vinegar because I like that zing in dressings, and I added a bit of finely chopped green onion. I also threw in some sliced ripe olives instead of putting it on the steak. And I sauteed the steak in a pan with some sliced onion. That being said, whatever you do, I doubt there is anything that can make this sauce less than great. The only change I made that I would recommend keeping is the green onion. And don't leave out the cucumber or tomato. I think the vegetables together are what gives it that wonderful greek street vendor sauce taste I haven't had since leaving New York over 10 years ago. I had forgotten how much I missed it, and the first bite brought it all back. Brenda, thank you for posting it! It brought back so many memories, and on a night I thought I was going to have yucky leftovers, I ended up having one of the best meals in a long time. I liked it so much, I might do it again tomorrow!