I love such soup, I really recomended it.
Heat the big pan, add the oil and chopped onion, fry until golden brown. Then add the crushed garlic, chicken breast cutted into cubes and fry 3 minutes, stirring at times. Pour in the coconut milk, chicken stock . Chop the tips of asparagus and put there to one side for later. Roughly chop the asparagus stalks and add into a pan. Put the all ingredients ( apart cream ) into a pan, as well. Bring to the boil and cook in a low heat for 15 minutes.
Add the tips of asparagus and cook another 3-4 minutes.( Take out the lemon grass) Pour the cream in, now is ready to serve .
Garnish with fresh coriander. It was very hot spicy soup.