Step 1

Tip the beans, corn, tomatoes, onion, pepper, avocado and coriander, if using, into a large bowl. (If not serving straightaway, add the avocado and coriander just before.)

Step 2

Drizzle over the olive oil and lime juice or vinegar and gently stir to combine. Season to taste. Will keep at room temperature for two hours, or chilled overnight, without the avocado and coriander. Serve with tortilla chips for scooping up.