Yes, you can use nectarines – they are great!
I don’t bother peeling peaches. Long live vibrant, colorful, fiber-rich peach skins!
If you don’t have lime, I’ve made this recipe using vinegar instead of lime juice and it works great. You just need some sort of acidic element. I used white balsamic vinegar, but apple cider vinegar or champagne vinegar work too.
