For the stew with Jerusalem artichokes and autumn trumpets, heat the oil in a heavy frying pan and sauté the onion, celery and carrot in it at a low temperature for 6-8 minutes until soft.
Set the vegetables aside and brown the meat. Stir in the flour and remove from heat. Gradually pour the clear soup and stir until the flour is completely dissolved.
Add the Jerusalem artichokes, mushrooms and olive paste and bring to a boil. Simmer gently over low heat for about 1 hour with the lid on. Add the lemon juice, season to taste and serve the Jerusalem artichoke and autumn trumpet stew with a mixture of long grain and wild rice and peas.