Blanch the broad beans in a pan of boiling water for a couple of minutes, then drain (keeping the water) and rinse under cold water. Set aside to cool.
Meanwhile, put everything else in a food processor.
When the broad beans are cool, remove their outer skins. Set a few beans aside for garnishing.
Add most of the beans to the food processor and whizz until you get a smooth paste, adding some of the cooking water. Season with salt and pepper to your liking.
Transfer the hummus to a bowl and garnish with the beans and drizzle with oil.