Put the beans, tomatoes, red pepper and spring onions in a food processor and blend until fairly smooth.
In a small bowl, whisk together the chilli, oil and vinegar, pour over the bean mixture and toss to coat. Season to taste with salt and pepper and garnish with coriander. Cover and leave to stand at room temperature for about 30 minutes to allow the flavours to mingle.
Serve the salsa with tortilla chips and soured cream.