Place the meat in a saucepan with water to cover, 1/2 onion, 2 cloves garlic and salt to taste. Bring to a simmer and simmer 1 hour. Remove meat (reserve stock) and shred with two forks.
In a blender puree the chilli, coriander, other 1/2 onion, 1 clove garlic, salt and a little meat stock.
Heat the oil in a frypan and brown the shredded meat slightly. Add the flour and stir in.
Pour the chilli mixture over the meat, add the potatoes and a little more meat stock. Cover and simmer over low heat until potatoes are tender.