Start by making the tomato sauce. Finely chop two of the garlic cloves and the onion and add to a saucepan with half of the olive oil. Sizzle on a medium high heat for two minutes, then pour in the red wine and allow to simmer down. Tip in the chopped tomatoes, add the mixed herbs and season with salt and pepper. Turn the heat to low and simmer while you prepare the courgettes.
Finely slice the remaining two cloves of garlic and finely chop the courgettes. Add to another saucepan with the remaining olive oil and cook on a medium heat for 8-10 minutes, until the courgette has started to soften. Then turn off the heat and stir in the ricotta.
To layer the lasagne, start with a spoonful of the tomato sauce, then a third of the lasagne sheets. Top with half of the courgette mix and half of the remaining tomato sauce, then another third of the lasagne sheets. Next, the remaining courgette mix, the last third of lasagne sheets and top with the last of the tomato sauce.
Slice the mozzarella and place evenly on top. Sprinkle with the grana padano. Bake in the oven at 180 degrees for 20 minutes, until golden and sizzling.