Tzatziki is traditionally made with Greek yogurt, lemon juice, garlic, herbs, and shredded cucumber.  I love tzatziki, but I question whether cucumber is the best vegetable for this dish; it can be a bit bland, and it weeps when salted.

Why not the beet instead?  Its earthiness provides a perfect compliment for the Greek yogurt, while its redness brings an invigorating personality to the color palette of a falafel sandwich.  Peeling and grating beets can be quite a messy business, but c'est la vie.  Put on that old shirt you've been meaning to throw away and just go for it, I say.  Read more.