Preheat the oven to 180 degrees Celsius.
Start by making the roux sauce. In a small saucepan add the plain flour, milk and butter. Heat gently and stir continuously until it forms thickened consistency. Add two tablespoons of parmesan, stir well and leave to one side.
Add your dried lasagne sheets to a large dish of boiling water. Arrange them in a criss-crossed pattern to avoid them sticking together and leave to soften.
To prepare the filling, finely chop the spinach and fry in garlic oil until cooked. Add the ricotta to a bowl, stir in the cooked spinach, parmesan and egg. Season with salt and pepper.
To prepare the tomato sauce, add garlic-infused oil, chopped tomatoes, tomato passata, tomato puree, dried oregano, basil and caster sugar to a small saucepan and stir well. Heat gently and leave to simmer for a few minutes.
To construct the cannelloni, put the spinach and ricotta mix into a piping bag, cut a hole and pipe a line along the centre of the longest length of the lasagne sheet. Carefully wrap the pasta and place into a large baking dish, with the fold facing down.
Repeat this until all of the lasagne sheets and filling have been used up, and you have a row of filled cannelloni tubes.
Pour the tomato sauce over the top of the cannelloni, ensuring the pasta is covered. Give the roux sauce a quick stir and pour this on top of the tomato sauce. Sprinkle generously with parmesan and bake for 25-30 mins.
Remove from the oven and serve with a green salad.