For the fennel-carrot casserole, finely chop the onion, cut the bacon into small pieces and fry everything in a pan with a little oil, then fry the finely noodled carrots and the finely chopped fennel.
(Save the fennel for garnishing) The vegetables should still be crunchy, but no longer hard. Grease the baking dish with butter and spread the vegetable mixture in it.
Sprinkle with finely chopped walnuts. Whisk 2 eggs with whipping cream, press in garlic cloves, season with salt, pepper and a pinch of freshly grated nutmeg.
Mix the grated cheese into the egg mixture and spread it evenly over the vegetables. Cover with aluminum foil and bake at about 200 °.
After about 30 minutes, remove the foil and let the surface brown (about 5 – 10 min.). Sprinkle with finely chopped fennel herb.