Peel the onions. Slice 1 onion into about 10 wedges and set aside. Roughly chop the other onion.
Add the chopped onion to a food processor with a pinch of saffron and 2 tbsp of the yogurt. Season. Blend to a chunky paste. (No processor? Grate the onion and stir everything together.) Pop into a shallow dish. Add the beef. Stir to coat. Set aside for 10 mins.
Wash the rice under cold running water. Tip it into a medium pan with 350 ml boiling water. Add a pinch of salt. Cover. Bring to the boil. Turn the heat right down. Simmer for 6 mins till the water is absorbed.
Drain the rice. Rinse out the pan. Melt the butter in the pan. Add a 2 cm layer of rice that covers the base of the pan. Heap the rest of the rice up to form a peak in the centre of the pan. Poke a couple of holes in the rice with a skewer.
Loosely cover the rice with baking paper. Pop the lid on the pan. Cook over a very low heat for 10 mins. While the rice cooks, halve the pepper. Deseed and chop into chunks. Zest the lemon. Juice it. Finely chop the parsley leaves and stalks.
Heat the grill to high. Line the grill pan with foil. Thread the beef, pepper and onion wedges onto the soaked skewers. Grill for about 10 mins. Turn every so often till the meat is browned on all sides and cooked through.
While the kebabs and rice finish cooking, halve the pomegranate. Hold one half in your hand over a bowl, cut-side down. Hit with a wooden spoon to shake out the seeds. Repeat with the other half. Stir most of the pomegranate seeds, parsley, lemon zest and all the juice into the rest of the yogurt. Spoon into a dish.
Put a plate over the rice pan. Turn it upside down. Hit the bottom of the pan to get the rice out. You may need to scoop the crust out with a spoon. Serve with the kebabs, rocket, yogurt and the remaining parsley, pomegranate seeds and lemon zest scattered on top.