Cut cauliflower up into florets and chop the courgette.
Add to a large roasting pan with the olive oil and salt. Roast for 20 minutes, then turn. Continue to roast for a further 20 minutes or until the veg is cooked and golden brown. Remove from the oven to cool.
To make the pestos
Blitz until you get a paste.
To serve
Toss the roast veg and butter beans in 3-4 tbsp pesto (more if you want).