Peel and roughly chop celery, carrots, leek, garlic, and ginger. Pluck the parsley leaves out of the stalks and set them aside.
Heat 1,5 l (1 ⅓ cups) water in a water boiler or on the stove. It seems like a lot of water, but some of it will evaporate during the cooking process.
In a large pot, heat vegetable oil on medium to high heat. Put in chicken thighs, garlic, and ginger. Roast for about a minute, stirring occasionally.
Pour in hot water and bring to a boil. Add ginger, turmeric, bay leaves, parsley stalks, salt and pepper. Stir and cover with a lid. Cook on low to medium heat for about 30 minutes.
Add chopped carrot and celery and cook for another 30 minutes, until the vegetables are tender.
Remove chicken thighs, celery stacks, ginger, garlic and bay leaves from the soup. Separate the meat from the bone, roughly chop and put it back into the soup.
Serve with soup noodles, the low-carb alternative zoodles, barley, or rice for a complete lunch or dinner.
Store in the fridge for up to 3 days or freeze for up to 3 months.