This one-pan lasagna is deliciously simple. It's a vegetarian main, is easy to make and it's saves washing the dishes. The recipes features loads of cheese, a bechamel sauce and lots of green vegetables. You could almost (but not quite) call it healthy.
Wash and slice the leek. Cut the cauliflower into small florets. Wash spinach if needed.
Melt the butter in a thick-bottomed pan (which can be placed in the oven). Gently sauté the leeks and after 3 minutes add the cauliflower florets. Cook over medium heat until almost tender. Add the spinach and let it wilt (drain excess water?).
Add the flour and mustard and stir well. Gradually add the milk, making sure it is well absorbed. Cook until thickened and season to taste with salt and pepper.
Stir in the garden peas and basil, followed by 80% of the Parmesan.
Tear the lasagna sheets into large pieces and push them into the sauce. Toss well to distribute and make sure some are on top, covered with sauce. Sprinkle the remaining parmesan and cheddar on top.
Place the pan in the oven and bake until the top is golden brown, 20 to 25 minutes.