Peel the onions and dice into cubes. Heat oil and fry the onions until soft. Add spelt berries and cook briefly.
Pour in broth and bring to a boil. Simmer 30 minutes.
Trim carrots and kohlrabi, peel, rinse and cut into slices. Add to spelt berries 8-10 minutes before end of cooking time.
Rinse lemon in hot water and grate the peel, then add to the soup. Squeeze juice from lemon. Mix double cream with lemon juice and stir into the soup.
Do not allow soup to boil. Season to taste with salt and pepper. Rinse chervil gently, pat dry and sprinkle the leaves over the soup.