Preheat the oven to 220°C (425°F) with a rack in the centre. Line a baking sheet with parchment.
Pat the chickpeas very dry, toss with the oil, cumin, smoked paprika, turmeric, cinnamon and salt, and spread in one layer.
Roast for 25 minutes, shaking the tray halfway, until crisp outside.
Rinse the quinoa and add to a saucepan with 480 ml (2 cups) of water. Bring to a boil over high heat, cover and simmer on low for 15 minutes, then rest 5 minutes.
Thinly slice the red onion and soak it in the apple cider vinegar for 10 minutes to pickle lightly.
Whisk the tahini and lemon juice with 3 to 4 tbsp of water until smooth and pourable.
Build the bowls with quinoa, chickpeas, diced cucumber and tomato and the pickled onion, then drizzle with tahini and finish with parsley and hemp hearts.