Rinse the basmati rice thoroughly under cold running water until the water runs mostly clear.
Place it in a bowl, cover with cold water and leave to soak for at least 30 minutes, then drain well.
Bring approximately 1.5 litres of water to the boil in a large pot. Stir in 1 tbsp oil, then carefully add the drained rice.
Boil uncovered for 6–8 minutes, or until the grains are 80% cooked and remain separate.
Drain the rice immediately in a colander and leave it to steam for 2–3 minutes. Gently fluff the grains with a fork and set aside.
Add all the ingredients for the marinade to a large bowl and mix until well combined.
Add the chicken and mix thoroughly until evenly coated in the marinade.
Cover and leave to marinate for at least 30 minutes.
Heat 50ml oil in a large wok over a medium heat.
Add the sliced onions and cook for 6–8 minutes, stirring regularly, until browned.
Remove a large handful of the onions and set aside for garnishing.
Stir the chopped tomatoes into the remaining onions and cook for 4–5 minutes until softened and beginning to break down.
Add the marinated chicken along with all of the marinade.
Stir well so the chicken is evenly combined with the onion and tomato mixture.
Cover the wok, reduce the heat to low and cook for approximately 30 minutes, stirring occasionally to prevent sticking.
Cook until the chicken is tender and completely cooked through.
Spread the cooked rice evenly over the chicken without stirring it into the sauce.
Then garnish with the reserved fried onions and chopped fresh coriander.
Cover with a tight-fitting lid and cook over a very low heat for a further 6-8 minutes, allowing the rice to finish cooking and absorb the flavours.
Remove from the heat and leave covered for 5 minutes.
Gently fluff the rice, before serving.