Corn & black bean salsa

Name: Corn & black bean salsa
Prep time: 10 min
Cook time: 45 min
Total time: 55 min
Cuisine: Latin American, Mexican
Ingredients: 140g dried black beans , soaked overnight; 326g or 330g can sweetcorn , drained; bunch spring onions , sliced; ½ large bunch coriander , leaves and stalks chopped, plus chopped stalks leftover from the Cheese & chilli melts (see 'Goes well with', below); juice 2 limes; 2 tbsp olive oil