Place on a baking tray and coat with a tablespoon of olive oil and seasoning. Place in the oven at 200c/180c fan/gas 6 for 25 minutes until slightly browned.
Place garlic and chopped onion in a pan with tomato puree, tinned tomatoes, until all softened. This can be pureed with a blender. Add the pulses.
Make up the white sauce by melting the margarine, adding the flour in whisking with a spiral whisk and adding the milk in slowly but stirring continuously so it doesn't go lumpy.
Reduce the oven temperature to 180c/160cgas 4. Arrange the vegetables in a bottom of a greased oven dish. Pour in a third of the tomato sauce. place a layer of lasagna sheets then drizzle over the white sauce. Repeat this until you have three layers finishing with a white sauce. Scatter the surface with the cheese.
Bake for 45 mins until brown and golden.