Heat oil in a frying pan and saute onion and garlic until soft.
Transfer to slow-cooker.
Stir in mince, salt and pepper, oregano, chilli flakes, beef stock, tomato paste, kidney beans and tinned tomatoes.
Cook, covered, on low for 6 hours. Then remove lid and put on high for 1-1.5 hours until mixture thickens.
To serve, melt tasty cheese on corn chips under the griller. Once golden brown, layer on top chilli con carne, guacamole and sour cream.
Notes
Chilli con carne is able to be served anytime after after cooking on low for 6 hrs if you prefer a thinner sauce. My family likes it thicker so the extra 1-1.5 hours on high with the lid off does the trick!