Heat oil and butter in a medium saucepan over medium to high heat
When the butter is bubbling add the onions - cook for 8 mins (don't brown)
Add carrot, bacon, rosemary - cook for 2 mins
Add celery and garlic - cook for 2 mins (don't burn the garlic you just want to release the flavour)
Add mince and brown – 8 mins. Breakdown the lumps with a fork
Raise heat and add stock
Bring to boil, simmer until liquid has reduced approx. 20 mins. (The longer the better so the mince soaks up the flavour)
Add oregano, salt, pepper, sage, red pepper flakes, and nutmeg
Cook for approx. 20 mins, stir occasionally so the bottom doesn't burn. Add a little water if the pan is catching
Add tomatoes, tomato puree and bay leaves.
Bring to the boil then simmer (very slowly) partially covered for about 2 to 4 hours (the longer the better), stirring occasionally to prevent catching.