For the Jerusalem artichoke-fennel casserole, first wash the fennel and Jerusalem artichoke (brush if necessary) and finely slice both. Chop the onion and fry in a little olive oil. Fry the fennel and Jerusalem artichoke.
When the vegetables are firm to the bite, add the walnuts and the very finely chopped ginger root and roast again briefly.
Put some olive oil in a casserole dish and spread the vegetables in it. Mix the eggs, cream, cream cheese and spices in a bowl until creamy and spread over the vegetables.
Bake in the oven at medium heat.