Cut the ciabatta in half horizontally. Drain the ball of mozzarella and cut it into 1cm slices. Drain the roasted peppers and cut in half.
Smear one side of the ciabatta with the pesto and the other with the harissa. Layer in the mozzarella, prosciutto and roasted red peppers, then stuff with handfuls of the rocket.
Heat a griddle pan or panini press over a medium-high heat. Put the ciabatta into the pan and put another heavy frying pan on top (if using the griddle pan), or shut the lid to press. If your griddle isn’t big enough, cut the panini in half to fit it in.
Toast for 2-3 minutes, then flip and repeat. Cut in half and serve with a big pile of crisps.
