Place the bread slices on a baking tray lined with baking paper, drizzle with oil. Roast the tray in the middle of the oven preheated to 240 ° C for 5 minutes.
Covering:
Let the oil warm up in the pan. Sauté the garlic, add the zucchini, continue steaming uncovered for approx. 15 minutes until the resulting liquid has boiled down completely. Let cool slightly. Add the basil and parmesan, puree, season.
Brush the crostini with the zucchini and herb mixture.