Clean and wash the broccoli and cut it into small florets. Cook in boiling salted water for about 7 minutes, then drain. Clean, wash and slice the mushrooms. Peel and finely chop the onions.
Wash and chop the basil. Heat the fat. Fry the onions and mushrooms for about 10 minutes while turning. Season with salt and pepper. Sprinkle with flour. Add stock and cream while stirring constantly, bring to the boil.
Season to taste with salt, pepper and nutmeg. Stir in basil. Pour some mushroom sauce on the bottom of a mould (approx. 20 x 30 cm). Spread 4 lasagne plates on top. Add some sauce again, then another 4 plates, some sauce and broccoli.
Add the sauce again and 4 more plates. Spread the rest of the sauce on top. Sprinkle with cheese. In a preheated oven (electric cooker: 200 °C/ gas: level 3), cover and cook for 30 minutes, then cook for another 15 minutes without foil.
Roast the pine nuts in a pan without fat and let them cool down. Garnish lasagne with roasted pine nuts and basil.