Sit the whole free-range chicken in a large, deep pan.
Carefully halve the butternut squash lengthways, then cut into 3 cm chunks, discarding the seeds.
Slice the coriander stalks, add to the pan with the squash, thai red curry paste and coconut milk, then pour in water. Cover and simmer on a medium heat for 80 minutes.
Use tongs to remove the chicken to a platter. Spoon any fat from the surface of the soup over the chicken.
Use a potato masher to crush some of the squash, giving your soup a thicker texture.
Taste, season to perfection with sea salt and black pepper. Shed the chicken and put the meat into the soup.
Fill bowls and sprinkle with the remaining coriander.