Tip the rice into a bowl, pour in enough cold water to cover it and set aside to soak while you prepare the curry.
Dice the halloumi into chunks around 1cm across. Warm a deep frying pan or wok over a medium heat for 2 mins, then add ½ tbsp oil and the halloumi. Fry for 5-6 mins, turning now and then, till the halloumi is browned all over.
While the halloumi fries, peel and finely chop the onion. Dice the tomatoes. Scoop the halloumi out of the pan and pop it on a plate lined with kitchen paper. Add the onion to the pan with 2 tbsp water and a pinch of salt and pepper. Cook, stirring now and then, for 5-6 mins till the onion has softened and picked up a little colour.
While the onion fries, peel and grate or crush the garlic. Finely chop the chilli, flicking out the seeds and white pith for less heat. Finely chop the coriander stalks (keep the leaves for later).
Stir the tomatoes, garlic, chilli and coriander stalks into the onion. Add 2 tbsp of the tikka masala spice blend. Cook and stir for 2 mins.
Stir the halloumi back into the pan. Drain the chickpeas and add them in. Crumble in the stock cube. Pour in 300ml boiling water. Pop a lid on the pan, bring to the boil and then turn the heat down a bit and simmer for 15 mins, stirring occasionally.
While the curry simmers, drain the rice and tip it into a small pan. Add 300ml boiling water and a pinch of salt. Cover, bring to the boil, then turn the heat right down and very gently simmer the rice for 8 mins till all the water has been absorbed. Take the rice off the heat and leave it in the pan, with the lid on, for 5 mins to steam the rice and finish cooking it.
Finely shred the spinach. Roughly chop the coriander leaves. Stir the spinach into the curry. Simmer, without the lid on, for 2-3 mins to wilt the spinach. Taste the curry and add a pinch more salt and pepper if you think it needs it.
Fluff the rice with a fork and divide between a couple of warm bowls. Top with the curry and garnish with the chopped coriander to serve.