Step 1
Preheat grill on high. Cook the combined capsicum, skin-side up, under grill for 6-8 mins or until charred and blistered. Transfer to a heatproof bowl. Cover with plastic wrap and set aside for 10 mins (this helps lift the skin). Peel.
Step 2
Preheat a barbecue grill or chargrill on medium. Brush zucchini, eggplant and pumpkin with the oil. Cook zucchini and eggplant, in batches, for 1-2 mins each side or until lightly charred and tender. Transfer to a bowl. Cook pumpkin for 2 mins each side or until tender. Transfer to the bowl. Set aside to cool slightly.
Step 3
Meanwhile, to make the rocket pesto, process the rocket, basil, pine nuts, parmesan and garlic in a food processor until finely chopped. With the motor running, add the oil in a thin, steady stream until well combined.
Step 4
Use a small serrated knife to cut the top third from each roll. Reserve the tops. Scoop out the bread, leaving a 1cm-thick shell. Spread the inside of each roll with the pesto. Arrange the capsicum, zucchini, eggplant, pumpkin, salami and brie, in layers, in the rolls. Spread cut-side of roll tops with pesto and place on top. Press down firmly.
Step 5
Place rolls on a baking tray. Top with another tray. Place cans on top. Place in the fridge overnight to compress the filling and develop the flavours.
Step 6
Preheat oven to 200°C. Uncover the rolls and bake on the tray for 10 mins or until crisp and golden brown. Serve warm or at room temperature.