Make the dumplings first so the flour can set a bit and swell. 5-10 minutes should do it. Combine flour and Herbs de Provence with salt, add water and whisk. Add oil and whisk again. The dumpling batter should be a creamy mixture, almost like a thicker sour cream. Add more flour if it is to runny or more water if it is too dense.
Heat a sausepan to medium. Add oil (or butter), chopped onions, mushrooms and garlic. Cook for a minute or two while stirring until the onions gets slightly translucent. Add and fry the meat at this point if you are having any. Pour in the stock and add carrots, potatoes (or your root vegetable), celery, bay leaves salt and black pepper. Let the soup boil under a lid, until the carrots are halfway cooked (about 5 minutes).
Make sure that your broth to soup bits ratio is more to the broth side since dumplings with suck up quite a bit of the liquid. Take a teaspoon of dumpling dough and carefully slide it into the boiling soup. Continue, until you are out of the dough. Cover the pot with a lid and let the soup boil on a medium heat for 7 – 10 minutes. Try to avoid opening the lid while the dumplings are cooking. In the end, add chopped parsley/spring onion/coriander and serve.