Method:

1. Preheat oven to 200C. Cook pasta in a large saucepan of boiling salted water until just tender. Drain.
2. Put spinach leaves into a large bowl. Cover with boiling water and stand for 2 minutes or until just wilted. Drain and rinse under cold water. Drain. Using your hands, squeeze as much liquid as possible from spinach. Finely chop.
3. Combine ricotta and milk in a bowl. Add 1 cup parmesan, egg, lemon rind, lemon juice, chopped spinach, salt and pepper.
4. Pour passata sauce into a shallow 5 cup capacity baking dish. Fill pasta shells with spinach mixture and place onto passata sauce. Sprinkle remaining parmesan over filled shells. Bake for 20 minutes or until parmesan is golden and pasta heated through. Serve.