In a pressure cooker cook the lamb for about 20 minutes.
In a small sauce pan boil guajillo peppers with onion and garlic. When it cools down blend it all together in a blender and pour the mixture into a large pot through a fine-mesh sieve pressing slightly.
Add salt and pepper to taste and bring to a boil.
Add some of the broth from the lamb and the vegetables and bring to a boil. The stew has to be thin, almost like a soup. If the lamb meat is still a little tough add to the pot, too.
When it starts boiling reduce heat to low and let it simmer for 25-30 minutes. Adjust seasoning if necessary.
Serve with slices of avocado, lime wedges and chopped onion and enjoy!
Recipe by Ben's blog at http://whatscookingmexico.com/2010/11/08/lamb-mole-de-olla/