Chipotle chicken tinga

Name: Chipotle chicken tinga
Prep time: 15 min
Cook time: 40 min
Total time: 55 min
Cuisine: Mexican
Ingredients: 2 tbsp olive oil; 2 onions , sliced; 2 large garlic cloves , crushed; 2-3 tbsp chipotle chilli paste; 400g can chopped tomatoes; 2 tbsp light brown soft sugar; 6 boneless, skinless chicken thighs; 1 small red onion , finely chopped; 3 ripe tomatoes , finely chopped; 1 lime , zested and juiced; 1 small bunch coriander , leaves and stalks finely chopped, plus extra leaves to serve; tortilla chips and guacamole, to serve