1 1/2 cups plain yogurt (all the recipes I found asked for special thick, Greek yogurt, but I used the regular stuff in the grocery store. It came out fine)
1/2 cup grated cucumber (it's hard to measure because it's so squishy, grate a couple inches of cucumber, and err on the side of too-much, rather than not-enough)
2 tablespoons lemon juice
garlic salt
chopped mint leaves
Most recipes I found called for 1 -2 tablespoons of olive oil as well, but I skipped that because it seemed like needless fat. The sauce was very smooth anyway. Maybe it's because I used the wrong yogurt!
I was a bit worried about experimenting with tzatziki sauce, as yogurt and lemon juice could easily make a curdled mess. But I love Greek food so I had to give it a go. I avoiding my curdling worries by grating the cuke into a tupperware container, and coating it in lemon juice, then garlic salt. Then I added the yogurt + mint.