Heat oven to 200C/180C fan/gas 6.
Put the tomatoes, cut-side up, in a large
roasting tin with the onions and top with
the chicken pieces. Season generously
and drizzle over 1 tbsp of the olive oil.
Roast for 45 mins until the chicken is
crisp and tender, and the tomatoes
start to caramelise.
When the chicken is ready, remove
from the oven to a plate and cover with foil. Use a slotted spoon to transfer the
tomato and onions to a food processor
and blitz until smooth. Reserve the
cooking juices from the roasting tin.
Heat the remaining oil in a medium
saucepan and fry the garlic, chillies and
coriander seeds for a few mins until just
brown. Pull the meat from the chicken
bones, tear into chunks and mix with
the beans, lime zest and chipotle paste.
Add this chicken mix to the pan but
reserve one-third of it. Pour the soup into
the pan and add enough of the cooking
juices until you get a nice consistency.
Heat a few inches of oil in a small
saucepan, then carefully shallow-fry
the tortilla pieces in batches until crisp.
Drain on kitchen paper.
To serve, gently reheat the soup,
season to taste and stir through the
coriander. Top with the reserved chicken
mix, avocados and lime juice. Serve
with the tortilla chips and soured
cream, if you like.