Slice the top third off the bread and scoop out the soft inside until you have a shell about 2cm (1in) thick (put the innards in the freezer to save for breadcrumbs or croutons).
In a bowl, mix the basil, oil, vinegar and some seasoning. Add the chicken, combine, then press the mixture into the hollowed-out bread. Top with the peppers, onion, cheese, rocket and then the tomatoes. Pack everything down and put the bread lid on.
Wrap tightly in clingfilm, put in the fridge and put a small chopping board on top, weighted down with something heavy such as large tins. Chill for at least 2 hours or overnight.
Unwrap and put on a board, then cut with a serrated knife.
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For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home.