In a non-stick pan, brown the onion and the mince beef over a medium high heat. Use a wooden spoon to break the mince apart.
When the mince is brown, put it in your slow cooker (small 3 qt is more than big enough). Add all the other ingredients too: pepper, celery, kale, PERi-PERi, tomato paste, basil pesto, paprika and cinnamon.
Pour in just enough water to cover the ingredients. Remember that water doesn't evaporate in a slow cooker, so all the liquid you put in will be there at the end - so just enough to cover.
Cook on the low setting for 8 hours, or 4 hours on the high setting.
Season to taste and serve with the toppings of your choice. Enjoy!