To make the lime-pickled onions,
combine ½ the lime juice and ½ the
onions in a small bowl, and season.
Leave to pickle for 30 mins.
Meanwhile, heat the olive oil in a
saucepan over a medium-high heat.
Add the garlic and remaining onions,
and season. Cook for 8 mins or until the
onions are translucent. Add the spices
and chipotle purée, cook for 1 min, then
add the beans, stock and remaining
lime juice. Simmer for 15 mins, then
purée in a blender.
Pour the soup into a clean pan to
reheat. Serve with a little of the drained
pickled onions, topped with a small
drizzle of soured cream and some
coriander, and the tortillas on the side.