Put a pan on a medium heat and add the rice, coconut milk, low fat milk and bring to boil. Reduce the heat and cover with a lid and cook gently for 8- 10 minutes stirring frequently until the rice is almost tender and milk is absorbed.
Add the water, cover and cook for a further 10 minutes until the rice is completely cooked.
Cut the fish into cubes.
Slice each of the lemon grass stalk in half lengthwise.
Cut the thin ends of each stalk to a point and thread the fish on to these skewers.
Separate the green and white part of the scallion.
Heat the oil in a large pan with the chilli flakes, garlic and white part of the scallion.
Add the fish skewers to the pan and gently fry for about 5 minutes turning until cooked through.
Stir in the vinegar, remaining scallion and the spinach.
Place the cooked rice on a plate and top with fish skewer.