As an alternative to the mozzarella filling, use feta cheese and watercress. Melt 1 tablespoon butter in a skillet over medium heat. Sauté 1/2 minced red onion, until soft, 3 to 5 minutes. Add 2 1/2 ounces watercress sprigs and sauté until the watercress just wilts, about 1 minute longer. Crumble in 3 ounces feta cheese, and season with nutmeg and black pepper.
Mozzarella contains less fat than many cheeses. For example, a 1 ounce serving of whole-milk mozzarella has 79 calories and 6.1 g fat, while the same amount of cheddar cheese has 113 calories and 9.3 g fat.
The Greeks and Romans believed eating watercress could cure madness. We, too, attribute healing powers to this green leaf, because it contains powerful phytochemicals that help to protect against cancer. It is also a good source of many B vitamins, plus vitamins C and E, and beta-carotene, which the body converts into vitamin A.
Per serving: calories 339, protein 40 g, fat 19 g (of which saturated fat 6 g), carbohydrate 1.5 g (of which sugars 1 g), fibre 1 g