Zucchini Souffle

Name: Zucchini Souffle
Yield: Serves 4
Ingredients: 1½ tablespoons dried breadcrumbs; melted butter, for brushing; 30 g (1 oz) butter; 2 tablespoons plain (all-purpose) flour; 125 ml (4 fl oz/½ cup) milk; 350 g (12 oz) zucchini (courgettes), chopped; 3 spring onions (scallions), finely chopped; 75 g (2½ oz) gruyère or parmesan cheese, finely grated; 4 eggs, separated