Put celeriac, carrots, parsnip and broccoli stalks (if using) in a large pan of salted water. Bring to boil and simmer until vegetables are tender.
Grate cooked veggies on a coarse/large side of the grater and set aside.
Put dried mushrooms in a small dish and pour over just enough boiling water to cover them (roughly 1/3 cup). Set aside.
Melt butter in a large pan and fry the onion until soft and translucent.
Add grated vegetables and mixed herbs and fry together with onion for approx 15 min.
Drain soaked mushrooms but keep the liquid. Chop them finely and add together with the liquid to the vegetables in a pan, mix well, season to taste and set aside for the mixture to cool a bit.
Once mixture cooled slightly, add beaten eggs, breadcrumbs and chopped parsley and mix well.
Put it in a buttered loaf tin and baked in 180C for approx. 50 min.
Let it cool and enjoy!