1) Split the aubergine in half through the stem and score sides. Drizzle with olive oil and season with salt. Griddle aubergine on a very hot griddle pan until skins are wrinkled and black and flesh side is nicely charred. When the aubergines are cool enough to handle, cut off tops.
2) In a food processor, combine aubergine, garlic, tahini, lemon juice, cumin, and coriander and puree until smooth. Season with salt and pepper. Pour in the olive oil and pulse again to incorporate. Taste and adjust seasoning, as needed. Pour into a serving bowl and garnish with a drizzle of olive oil and some roughly chopped coriander. Serve with pita strips for dipping.
To make pita strips:
1) Preheat oven to 190C/Gas 5. Put the pita strips in a large mixing bowl. Combine za'atar spice mix and extra-virgin olive oil and drizzle over wedges. Season with salt and toss to coat evenly.
2) Lay out strips on a roasting tray and bake in the hot oven for 10 to 15 mins until warmed through. If you prefer a crispier pita, bake for a further 5 to 7 mins. Serve warm with baba ghanoush.