Joudjeh kabab (Persian-style chicken kebab)

Instructions

1. Finely grate the onions and press them in a sieve to collect their juice.
2. Mix the grated onion, onion juice, lemon juice, steeped saffron, oil, salt, pepper and turmeric in a large bowl.
3. Cut the chicken into cubes or thin strips, add it to the marinade and mix well. Cover and refrigerate for at least 2 hours, ideally overnight.
4. Thread the chicken onto skewers, pressing the pieces together lightly.
5. Heat the oven grill or a grill pan. Cook the skewers for 8 to 10 minutes, turning them, until the chicken is golden with no pink at the center.
6. Meanwhile, halve the tomatoes, place them cut side up on the tray and grill for 5 minutes with a little butter.
7. Cook the rice in salted water, then drain it and toss it with a little steeped saffron and a knob of butter.
8. Serve the chicken on the saffron rice with the grilled tomatoes, sprinkled with sumac if you have some.