Tzatziki Sauce
I tried this recipe on a whim the other night and it was really good. The only downside was that I only had enough yogurt to make half a batch! You can use it as a dip, put it on sandwiches, whatever your heart desires. It's made with Greek yogurt so it's pretty healthy and is a great source of protein. (Note: I'm a huge fan of Fage 2% yogurt; it's a staple in my fridge.)
This photo is stolen from the website because mine was gone so quickly I never got one!