Saffron chicken kebab (Joojeh kabab)

1. Grind the saffron to a powder in a mortar with a pinch of sugar and steep in 3 tbsp hot water for 10 minutes.

2. Cut the chicken breast into 4 cm cubes. In a bowl mix the yoghurt, the grated onion with its juice, the lemon juice, oil, salt, pepper and half of the saffron water.

3. Toss the chicken in it, cover and refrigerate for at least 4 hours, preferably overnight.

4. Thread the meat onto skewers and cook on a hot grill or griddle pan for 10-12 minutes, turning several times.

5. Mix the melted butter with the remaining saffron water and brush the skewers with it during cooking and again at the end.

6. Serve with saffron basmati rice, grilled tomatoes and sumac.

Tip: Joojeh kabab is the favourite of barbecues in Persian gardens. Always grate the onion rather than chopping it: its juice tenderises the meat. With chicken thighs it turns out even juicier and dries out less on the grill.