to serve:
place onion, garlic, red chilli and tomatoes in a blender and make a smooth paste.
heat the oil in large saucepan and add the paste and the allspice. cook for a couple of minutes, stirring constantly, until the mixture becomes fragrant.
pour the stock into the pan, add the lime lime rind and juice and tomato puree. add about a litre of water, bring to the boil and cook for 15 - 20 minutes. adjust the flavour with more lime juice.
serve with the fried tortilla strips, avocado, spring onion and coriander.