Heat oil in a heavy-based saucepan and fry onions for 3 minutes.
Add pepper and sweet potato and fry for another 4 minutes.
Sprinkle ground coriander and flour over vegetables and stir for 40 seconds.
Stir in tomatoes, chipotle paste, beans, 600ml water, salt, and pepper.
Simmer for 20 minutes until vegetables are tender, stirring regularly.
Boil quinoa in a separate saucepan for 15 minutes or until tender.
Cut avocado into chunks and toss with lime juice.
Drain quinoa and let cool in a bowl for 5 minutes.
Fluff quinoa and stir in avocado, spring onions, and coriander.
Serve the stew over the quinoa with a dollop of soured cream.