Preheat the oven to 220°C (430°F). Line a large baking sheet with parchment paper and set aside.
Thinly slice the zucchini and place onto the baking sheet. Add the oil, salt, pepper, sumac, and hot pepper flakes. Mix well to coat the zucchini.
2 medium zucchini, 2 teaspoons oil, ½ teaspoon sea salt, ½ teaspoon black pepper, ½ teaspoon sumac, ¼ teaspoon hot pepper flakes
Roast for 30-40 minutes, stirring the zucchini at the halfway mark. If it's browning too quickly, reduce the heat to 200°C. Check the bottoms of the slices - some ovens are much hotter from below.
Mix the yoghurt, lemon zest and juice, garlic, and salt in a bowl. Transfer to a large serving dish (or keep separate to serve individually). Top the yoghurt with the roasted zucchini and serve immediately, with something like red lentil pancakes.
200 grams (¾ cup) Greek-style yoghurt, 1 lemon zest and juice, 1-2 cloves garlic, ¼ teaspoon sea salt
This is pretty good cold and can be stored in a sealed container in the refrigerator for a day or two.