I often throw a couple of mild red chillies in to roast with the sweet potatoes. They will char nicely, and you can just chop and scatter them over the finished salad.
Preheat the oven to 200°C/180°C fan. In a large bowl, whisk the za’atar into the olive oil. Cut the sweet potatoes into even 2cm cubes and mix into the spiced oil along with the beans, garlic and half a teaspoon of salt. Then tip everything onto a roasting tray in a sing