Instructions

1. Peel and de-seed the squash, then cut the flesh into 2cm cubes. Heat 1 Tbsp olive oil in a frying pan, add the rosemary and the diced squash and cook at a low temperature for about 10 -15 minutes until soft. Drain, rinse with water, then drain again. Set aside.
2. Cook the shell in boiling, salty water, following the packet instructions. Do not overcook - the pasta should be al dente. Drain and set aside.
3. In a pan, heat 2 Tbsp of oil and gently sauté the chopped onion and garlic, until soft and translucent, then add the passata. Bring it the boil and gently simmer for about 15 minutes until you get a thick sauce.
4. Meanwhile, place the drained pasta shells in a baking tray, facing upwards. Mash the squash with a fork and season with salt and pepper to your liking. Fill the shells with this mash.
5. Turn on the oven, setting the temperature to 200°C.
6. Now make the béchamel sauce: heat the butter in a pan, add the flour and nutmeg and stir constantly with a mini whisk so as not to get lumps. When it's thick, remove from the heat and gradually add the milk, stirring the sauce constantly! Return to the stove and keep stirring at a low temperature for about 5 minutes until you get a thick sauce.
7. Pour the tomato sauce on top of and around the stuffed shells then pour over the béchamel sauce. Scatter the grated cheese on top.
8. Bake in the oven for 15 minutes until golden brown.
9. Serve warm.