Low calorie and healthy broth.

2tbsp olive oil
2 leeks
3 carrots
3 celery roots
400gr. mushrooms
1 onion
1/2tsp black pepper
1/2tsp thyme
3 parlsey roots
3500ml water

Cut all of the vegetables.Peel the carrots before cutting.
Preheat a medium pot on a medium heat and add the olive oil.
Add the vegetables to the pot and steam a little bit.Add the water to them.
Leave the stock to boil.After its  become to boil,reduce the heat to low and simmer for 30min.
When the stock is ready,strain it and store in cold place.You can freeze it if you want.