Heat the oven to 220C/200C fan/ gas 6. Pour 800ml just-boiled water into a heatproof jug, crumble in the stock cube and stir in along with half the curry paste and the butter or oil. Pour the mixture into a large baking dish or roasting tin (ours was 25 x 35cm and 5cm deep), and tip in the rice and cinnamon stick. Season and stir well.
Cut a few deep slashes into each chicken thigh, then rub all over with the remaining curry paste and some seasoning. Arrange on top of the rice mixture, then cover the dish or tin with foil and bake for 30 mins.
Meanwhile, heat a drizzle of oil in a frying pan over a medium heat, and fry the onion for 10-15 mins, or until soft and caramelised.
Uncover the chicken and rice. The rice should still be wet, but if not, top up with 50-100ml more water. Scatter over the almonds and bake, uncovered, for 10-15 mins more until the chicken is browned, all the liquid has been absorbed and the rice is cooked through and crisp at the edges. Meanwhile, cook the green beans in boiling water for 2-3 mins, then drain. Scatter the coriander and fried onions over the chicken and rice, spoon a few dollops of chutney over the dish, and serve with the green beans.