Peel and finely dice the onions, then place them into a microwaveable mould and steam them in the microwave for 2-3 minutes at 900 watt.
Add the minced meat, peeled tomatoes, minced garlic clove, herbs and seasoning to the onions. Cook for 8 minutes at 900 watt without covering. Now and then, give it a good stir. Season with salt and pepper.
Place the margarine into a second microwaveable mould, cover, and melt in the microwave for approx. 1 minute at 900 watt. Add the flour and milk and mix well. Heat for 3 minutes at 900 watt and then add 30 g Parmesan and Emmental cheese, once again mixing well.
Grease a microwaveable oven dish with oil. Assemble the lasagne sheets, minced meat sauce and ricotta cheese in alternating layers. Then pour the cheese sauce over the top layer and sprinkle the remaining Parmesan on top. Cover the oven dish and cook for 4 minutes at 900 watt. Then, uncover and cook for a further 10 minutes on the grill function. Garnish with basil and serve.