Clean, halve, wash and slice the fennel. Clean and wash the carrots and spring onions. Cut carrots into slices, onions into rings. Cover the fennel and carrots and cook in little boiling salted water for 6-8 minutes. Drain the vegetables. Chop nuts coarsely.
Peel garlic, crush finely. Whisk with eggs and cream and season with salt and pepper. Layer vegetables in a greased casserole dish, pour leek onions, nuts and egg cream over them. Seal with aluminium foil and bake in a preheated oven (electric cooker: 200°C/ gas: level 3) for approx. 40 minutes. During the last 5 minutes remove the foil and sprinkle the grated cheese over the gratin. Finish cooking in the open pan