Bring the vinegar, sugar and water to the boil.
Remove from the heat and season.
Add the finely sliced red onion, mix well and put aside until serving.
Now, add the oil to a large heavy-based dish and brown the venison mince.
Add the onions and garlic and cook for 3-5 minutes until slightly softened.
Add the spices and cook for another minute, before adding the tomato paste.
Cook for a further two minutes and then add the sugar and vinegar. Reduce for about 2 minutes.
Finally, add the chicken stock and bay leaf, and simmer slowl until the stock has evaporated.
Remove from the heat and allow to rest for 10 minutes.
Warm the tortillas and place a generous spoonful of the ground venison in the centre of each.
Top with a spoonful of guacamole, sprinkle on the crispy onion, coriander and pickled red onion. Arrange on a plate and serve immediately.