Wash the rice until the water runs clear, then drain well.
Melt the butter in a saucepan set over a medium heat. Add the orzo and toast for 5-10 mins, stirring regularly, until deeply golden. Stir through the rice, then pour in the water. Bring to the boil, then pop a lid on, reduce the heat to low and cook for 12 mins. Once the time is up, remove the pan from the heat and leave it to steam for 10 mins with the lid on.
Meanwhile, split the halloumi down the crease and chop into 2cm chunks. Halve any larger mushrooms. Peel and finely grate the garlic into a bowl. Stir through the yoghurt, tomato purée, and Al'Fez Shawarma Spice Mix to taste. Season with salt, then toss in the halloumi and mushrooms until well coated.
Line a baking tray with baking parchment. Tip the marinated halloumi and mushrooms onto the tray and spread out. Roast for 15-20 mins, until golden and starting to char. Peel and finely slice the red onion, then toss it with the sumac (if using) and a pinch of salt. Set aside to soften slightly.
Pick the parsley leaves and finely slice the stalks and half the leaves. Once the rice is ready, fluff it with a fork and stir through the chopped parsley. Season to taste.
Divide the rice between bowls and top with the roasted halloumi and mushrooms. Finish with the sumac onions, parsley leaves and a generous drizzle of Al'Fez Tahini Squeezy Sauce.
