- Preheat the oven to 190°C/gas 5. Trim the ends from the courgettes, then take off thin strips of skin, lengthways, to achieve a striped effect. Cut across into pieces 4cm long and remove the soft centre flesh with a 3cm round cutter or by hollowing out with an apple corer or small sharp knife. Finely dice the removed courgette flesh and set aside.
- Put the courgette rings in a bowl and pour over enough boiling water to cover. Leave for 2 minutes, then drain in a colander and arrange them, upright, in a single layer in a large ovenproof dish.
- Heat the oil in a frying pan and gently cook the shallots or onions and garlic for 3–4 minutes, until beginning to soften. Add the garlic, fennel and diced courgette flesh and continue cooking over a low heat for a further 5 minutes until they are almost tender. Remove from the heat. Stir in the chopped tomatoes, the cannellini beans, the coriander and the chilli flakes, if using, then season to taste.
- Spoon the bean mixture into the courgette rings, piling it up on top. Pour the stock into the dish around them. Cover with a ‘tent’ of foil, tightly sealing around the edge, but allowing space for the courgettes to steam. Bake the courgettes for 30 minutes.
- Remove the foil and sprinkle the tops with a mixture of the breadcrumbs, walnuts, cheese and a little freshly ground black pepper, if liked. Return to the oven and bake, uncovered, for a further 15–20 minutes until the courgettes are very tender and the tops are crisp and brown.
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.
When marrows are in season, use them in place of courgettes. Peel and cut a 1.5kg marrow into 9 rings, then scoop out and discard the seeds. Finely chop the flesh of 1 slice to add to the stuffing mixture, made with butter beans instead of cannellini. Stuff the remaining rings and bake as in the recipe.