Step 1
Place the potatoes in a large saucepan and cover with water. Bring to the boil over high heat. Cook for 10 mins or until just tender. Drain well.
Step 2
Meanwhile, heat grill on high. Place capsicum, skin-side up, on a baking tray. Cook under the grill for 5-7 mins or until skin blackens and blisters. Transfer to a heatproof bowl. Cover with plastic wrap. Set aside for 5 mins to cool slightly (this helps lift the skin). Peel and thinly slice.
Step 3
Place the coriander, parsley, mint, oregano, garlic, pine nuts, parmesan and vinegar in a food processor and process until finely chopped. With the motor running, add the oil in a thin, steady stream until well combined. Season the pesto.
Step 4
Heat a chargrill on medium-high. Cut potatoes in half lengthways. Spray with olive oil spray. Cook for 2 mins each side or until lightly charred. Transfer to a plate. Cook the chorizo and tomatoes, turning, for 2 mins or until the chorizo is golden and tomatoes begin to collapse.
Step 5
Combine potato, chorizo, capsicum, rocket and 2 tbs pesto in a large bowl. Arrange on a serving platter. Top with tomatoes. Drizzle with remaining pesto. Serve warm or at room temperature.
Serve with oregano leaves.
Get ahead: Make the pesto up to 1 day ahead. Store in an airtight container in the fridge.