Take spinach out of the freezer in time and let it defrost. Wash the zucchini, dab dry and cut into slices. Mix ricotta, cream and starch and season with salt and pepper.
Pre-cook the lasagne sheets in boiling salted water for 4-5 minutes, then rinse with cold water, mix carefully with a little oil. Wash the basil, dab dry and cut the leaves of 2 stems into strips.
Cut salmon into thin slices. Heat the butter, sauté the spinach for 2-3 minutes, then season with salt, pepper and a little nutmeg. Finally add the basil strips to the spinach. Spread the bottom of the casserole dish with ricotta cream and cover with 3 lasagne sheets.
Place half the spinach, courgette and salmon strips on the lasagne sheets and spread 1/3 of the ricotta cream on top. Layer 3 lasagne sheets, rest of spinach, courgette and salmon and spread with 1/3 of the ricotta cream.
Finish with 3 lasagne sheets and the remaining ricotta. Sprinkle the surface with pine nuts and cheese and bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 20 minutes.
Remove the lasagne from the oven, garnish with the rest of the basil and serve immediately.