Creamy courgette lasagne

Ingredients (4 servings): 9 dried lasagne sheets 1 tbsp sunflower oil 1 onion, finely chopped 700g courgettes (about 6), coarsely grated 2 garlic cloves, crushed 250g tub ricotta 50g cheddar 350g jar tomato sauce for pasta   Method: Heat oven to 220C/fan 200C/gas  Put a pan of water on to boil, then cook the lasagne sheets…