Method

• 1.
  Heat a barbecue or chargrill pan to high heat. Grill tomatoes, turning occasionally, for 10 minutes or until charred. Add spring onion and grill, turning halfway, for 2 minutes or until charred.
• 2.
  Transfer tomato and spring onion to a tray and set aside until cool enough to handle. Peel and discard tomato skins (don’t worry if a few little bits remain; they’ll only add to the flavour) and chop spring onion.
• 3.
  Whiz tomato, spring onion, half the lime juice and coriander leaves in a blender to a chunky paste.
• 4.
  Place chilli in a fine sieve and rinse under warm water to remove the seeds. Transfer chilli to a bowl with vinegar, oil, coriander stalk and remaining lime juice, and stir until well combined.
• 5.
  Spoon the salsa into a serving bowl, top with pickled chilli mixture and serve with tortilla chips.