1. Heat your oven to 200°C/Fan 180°C/Gas 6. Scrub the beetroot and chop into 1cm cubes. Peel and quarter the onion. Drain and rinse the chickpeas. Tumble the beetroot and onion onto a baking tray lined with baking paper. Tip on half the chickpeas and drop on the unpeeled garlic cloves. Scatter over 1 tbsp cumin seeds. Drizzle over 1 tbsp oil and plenty of seasoning. Toss to mix. Roast for 30 mins.
2. Meanwhile, make your flatbread dough. Tip the flour into a large bowl, reserving 1 tbsp. Add a pinch of salt and ½ tbsp oil. Pour in 4 tbsp cold water. Mix and knead to a smooth dough, adding extra water if it needs it. Cover and set aside to rest.
3. Tip the remaining chickpeas into a food processor. Zest the lemon and set the zest to one side. Juice in half the lemon and add the tahini. Set the processor aside.
4. Cut the halloumi into 1-2cm cubes. Finely chop the mint leaves. Finely chop the parsley, stalks and leaves, keeping the leaves and stalks separate.
5. Remove the beetroot from the oven after 30 mins. Lift half the beetroot into the processor. Turn the oven off but place the tray with the remaining beetroot and chickpeas back in the oven to keep warm.
6. Squeeze the garlic flesh into the processor. Add the parsley stalks. Blend to a chunky paste. Slowly trickle in 2-4 tbsp cold water till the hummus is as smooth as you like. Taste and season.
7. Dust your worktop with 1 tbsp flour. Roll the dough into 2 balls. Roll them out as thinly as possible – they should be about the size of a dinner plate. Place a frying pan on a high heat. When hot, place a flatbread into the pan and cook for 1 min. Flip over and cook for 1 min, till golden brown and bubbled. Repeat with the other flatbread. Pop in the oven with the chickpeas and beetroot.
8. Place the frying pan back on the heat. Pour in ½ tbsp oil and add the halloumi. Fry for 4-5 mins, tossing regularly, till golden. Sprinkle over 2 tsp sumach and toss for 1 min. Tip onto a plate.
9. Place each flatbread on a plate. Top with the beetroot hummus, roast beetroot onion and chickpeas, halloumi, herbs and zest. Finish with the sprouts and drizzle 1 tsp oil over each. Serve with the remaining lemon, cut into wedges.