Melt the butter, stir in the flour and add the milk, let it thicken briefly and then add the vegetable stock and white wine. Cook for approx. 7 minutes, if the sauce thickens too much, add a little milk. Dissolve the cream cheese and Gorgonzola in the hot sauce. Cook for another 5 minutes, adding the spices. Add the spinach, bring to the boil briefly and, if necessary, dilute again with milk. Since the lasagne plates soak up some of the sauce, the mass should not be too thick.
Cut the onions into rings and brown them well.
Layer the lasagna in a large baking dish as follows:
- Spinach mixture so that the bottom is just covered
- Lasagne sheets
- half of the grated cheese
- Spinach mixture, again just thin
- Sliced tomatoes
- fried onions
- Lasagne sheets
- remaining spinach mixture
- Mozzarella, sliced
Bake in the oven for 45 minutes at 170 ° C.
Since the lasagna tastes better when warmed up, you can only put it in the oven for 30 minutes at 180 ° C, then let it cool down and cover it with aluminum foil and heat it for another 35 minutes at 160 ° C the next day.