- Wash the spinach well and place the wet leaves in a large saucepan. Cover and cook over a high heat for about 3 minutes, shaking the pan frequently. When the spinach is just tender and wilted, tip it into a colander and leave it to drain and cool.
- Meanwhile, place the courgettes and half the garlic in a saucepan. Pour in the stock and bring to the boil. Cook over a high heat for about 3 minutes or until the courgettes are just tender.
- Purée the courgettes and stock in a blender or food processor until smooth, adding half the ricotta cheese, the walnuts, 2 tbsp Parmesan cheese and seasoning to taste. The resulting sauce should have a consistency halfway between single and double cream, slightly more runny than a coating sauce should be.
- When the spinach is cool enough to handle, squeeze it dry in small handfuls and chop it coarsely. Mix the spinach with the chervil or marjoram, chives or shallots, basil, the remaining garlic and ricotta cheese, the egg and seasoning to taste.
- Preheat the oven to 190°C (375°F, gas mark 5). Use a small teaspoon to stuff the pasta shells with the spinach mixture, and arrange them in an ovenproof dish.
- Pour the sauce over the stuffed shells and sprinkle with the remaining grated Parmesan. Cover the dish tightly with foil and bake for 30 minutes.
- Sprinkle the Edam cheese and basil over the cooked stuffed pasta and leave to stand for 5 minutes, uncovered, until the cheese melts, then serve.
Parmesan cheese is not truly vegetarian, as it contains animal rennet. To make this dish 100% vegetarian, omit the cheese or find a suitable vegetarian substitute made without animal rennet. In supermarkets look for the 'parmesan style hard cheeses' which are suitable for vegetarians.
Some more ideas
All sorts of greens can be used in this filling to replace some or all of the spinach and herbs. Try beet tops, Swiss chard, fresh borage and dandelion leaves. Raid your own herb garden or explore the greenery counter in the supermarket for exciting, vitamin-packed combinations.
Walnuts are a good source of polyunsaturated fat and essential fatty acids. Some studies indicate that eating a small quantity of walnuts daily combined with a low-fat diet can help to reduce high blood cholesterol levels. Walnuts also provide useful amounts of vitamin E, many of the B vitamins, potassium and protein.
Each serving provides
A, calcium * B1, B2, B12, C, E, folate, niacin, copper, potassium * B6, iron, selenium