Preheat the oven to 220 degrees Celsius/ 430 degrees Fahrenheit.
Spices mix: In a small bowl, mix the sumac, cumin, thyme, sesame seeds, and salt.
Prepare beets: Scrub the beetroots very thoroughly, dry them, and cut them into wedges. Spread the drained chickpeas and the beetroot wedges on a large baking tray, add the olive oil and mix well with your hands.
Roast: Add half of the spice mix to the beetroots and the chickpeas and mix again thoroughly. Roast for about 25-30 or until crisp at the edges. Check towards the end of the roasting time so that the chickpeas will not turn black. They should be nicely crisped, and the beetroots should be a bit softer but not too soft or mushy.
Yogurt: In the meantime mix the yogurt with the lemon juice and zest and about 1 teaspoon of the remaining spice mixture. Swirl the harissa through and spread the yogurt on a serving platter.
Serve: Top with beetroot wedges, chickpeas, and mint leaves. Drizzle a little olive oil on top and sprinkle with a pinch of the spice mixture. Enjoy with some crispbread.
Read the blog post for more information on sumac and harissa.
The spice mixture will be more than you need for this dish. You could make only half of it if you wish or you can use the rest to add to other dishes. The mixture will keep well for several weeks.