In a frying pan on medium-high heat, add butter followed by diced onion and cook for 5-7 minutes until translucent
Add chopped garlic, tomato paste, Italian seasoning, salt and pepper, and stir and cook for about a minute
Add chopped tomatoes, sugar and fresh chopped basil, then simmer for 15-20 minutes on medium-low heat until sauce thickens
Taste and season the sauce to preference
Pre-heat oven to 180C/350F
Wilt spinach in a large pan and drain well, squeezing out excess liquid with cheesecloth or towel
Roughly chop the spinach and add to a bowl with ricotta, lemon juice, zest, milk, salt and pepper
Taste and season the spinach mixture to preference
In a square baking tray, layer: tomato sauce, lasagne sheets, spinach and ricotta mix, mozzarella, cheddar, tomato sauce, and lasagne sheets
Repeat the layering process using three layers of pasta
Top with more cheese and cover with tin foil
Bake for 20 minutes covered, then remove foil and bake for another 10-15 minutes until top is golden
Serve with grated parmesan, drizzle of olive oil and pepper
