Take a heavy bottomed pan, pour in the water and chicken broth together and let it simmer.
Next add in the boneless chicken pieces and cook for 5 to 6 minutes without covering the pan.
After this time period, remove the pan from the stove and cover it for 15 minutes, during this time the chicken will get cooked.
Now move the chicken to a dry plate and let it cool down for 10 minutes or so. Make sure to save the chicken broth as this will be required later.
In the meantime, take a heavy pot and heat oil in it. Once the oil is heated, put in the chopped onion and cook till it is soft and translucent in colour.
Then add in the minced garlic and fry it till a strong aroma emerges. Put in the chopped carrots, green beans, salt, pepper and cook for 7-8 minutes.
Next add in the chicken broth, lower the heat and let it simmer for 8-10 minutes till the vegetables are soft.
In a separate pan, bring water to a boil and add in the white noodles. Cook for 5-8 minutes, once cooked strain and keep aside.
Meanwhile also shred the chicken into 1 inch long strips with the help of a sharp knife.
Finally put the shredded chicken and white noodles into the vegetable soup and cook for 1-2 minutes.
Serve hot with a garnish of lemongrass strands.