Step 1: 1) put around 2 tbsp oil on a baking tray and place in a hot oven of about 200 degrees
Step 2: 2) after about 5 minutes, throw the peppers and onions on the tray, give everything a toss and put back in the oven for 30 minutes.
Step 3: 3) finely chop the spinach then add to a bowl and spoon in the ricotta and mix together. Set aside.
Step 4: 4) meanwhile, fry the garlic in a little oil then add the chopped tomatoes and puree and heat through on a low heat.
Step 5: 5) in another saucepan, melt the butter then add the flour and give it a whisk and gradually add the milk and 50g of the cheese. You might not need all the milk, as the sauce needs to be nice and thick.
Step 6: 6) spoon a few tablespoons of the tomato sauce into the bottom of a deep baking dish (the one you want to cook the lasagna in).
Step 7: 7) check on the veggies in the oven, they should be cooked and slightly crispy at the edges. Throw them into the rest of the tomato sauce then you can start to asemble the lasagna.
Step 8: 8) cover the bottom of the dish with the lasagna sheets, then spoon on a thick layer of the spinach then a layer of the chunky veggie tomato sauce. Repeat till you run out, then spoon the cheese sauce ontop, sprinkle the rest of the cheese and bake for 40 minutes at 180c degrees. Serve with garlic bread.