Preheat oven to 180°C (350°F). Cut the chicken breasts into bite-sized chunks. Sprinkle with the spices and season to taste with salt and pepper.
Chop the broccoli into small florets, roughly the same size as the chicken. Bring a pan of salted water to the boil and add the florets to the water. Bring back to the boil and simmer for 1 minute.
Place the spring onions, coriander, jalapeños and yoghurt into a blender. Add seasoning to taste. Blend until smooth.
Mix together the chicken and broccoli with ¼ cup of the sauce. Cover the base of a large baking dish (about 9" x 13") with a thin layer of sauce.