Prepare Courgettes: Wash the courgettes and cut them lengthwise. Using a melon baller or spoon, scoop out the pulp carefully, leaving a thin shell. Reserve the pulp for the filling.
Cook Filling Base: Chop the courgette pulp roughly. Chop the spring onions. Heat some olive oil in a pan, sauté the spring onions for about 3 minutes, then add the courgette pulp with a pinch of salt. Cook over high heat for 10-12 minutes until the liquid reduces.
Prepare Filling: Transfer the cooked pulp and spring onions to a bowl. Add chopped sun-dried tomatoes, coarse breadcrumbs, chopped fresh basil, and grated cheese if using. Mix well to combine.
Stuff Courgettes: Lightly grease a baking tray. Arrange the hollowed courgette shells on it. Press the filling lightly between your hands and stuff the courgette boats generously. Flatten the surface for a neat appearance.
Add Topping and Bake: Sprinkle extra coarse breadcrumbs on top of each stuffed courgette and drizzle with olive oil for browning. Bake in a static oven at 200°C (392°F) for 30 minutes.
Serve: Remove from oven, garnish with fresh basil leaves, and serve warm.