Preheat the oven to 220°C/fan 200°C/gas mark 7. Cook the pizza base for 10 minutes. Remove from the oven, leave to cool and wrap in foil to transport.
Meanwhile, tip the peppers into a lidded plastic container and add the tomatoes and mozzarella. Pack in a cool bag with the rocket and an ice pack to transport to your picnic. When ready to eat, top the pizza with the antipasti mix and scatter over the rocket leaves.