Pour a splash of oil into a wide frying pan set over a medium heat. When hot, add the broccoli, cut sides down, and the sliced halloumi.
Cook both for a couple of minutes a side, until the halloumi is browned all over and the edges of the broccoli are beginning to char.
Meanwhile mix together the tahini, extra-virgin olive oil, lemon juice and a little pinch of salt – it may thicken up, in which case add the water to thin the mixture to make a just-about pourable dressing.
Remove from the pan and set aside. Spoon the chickpeas directly from the tin into the hot pan, leaving most of their liquid behind (to store them in). Add the harissa and warm the chickpeas, stirring to coat them in the harissa.
Arrange the chickpeas on the bottom of a plate or bowl and add the broccoli and halloumi. Drizzle over tahini dressing, and finish with the pomegranate seeds, if using. Eat while the halloumi is hot.