Here's mine - been a success since student days.
Take courgettes, mushrooms, onion. Chop them and fry them with crushed garlic.
Add tin of chopped tomatoes, or use skinned fresh ones if you can be bothered.
Add two big handfuls of fresh spinach and allow to cook down - about 2 mins.
Add a good handful of basil, preferably fresh, few twists of black pepper, and teaspoon of brown sugar.
Leave to simmer for 10 mins or so while you sort out the cheese sauce.
Cheese sauce:
Melt tablespoon of butter in saucepan and mix with enough flour to make a thick paste. Add milk, approx. half a pint or so depending on how thick you like your sauce) and stir with balloon whisk until milk is just reaching boiling point. Remove from heat and add two handfuls of grated cheese.
Pour veg mixture into bottom of lasagne dish, top with enough sheets of lasagne pasta to cover, then top with half of cheese sauce. Repeat. Sprinkle more grated cheese over top and bake in oven at gas 6 for 20 mins or so, until pasta is cooked and cheese is golden and bubbly.
Remove from oven and eat with big salad and garlic bread - yum.