Heat up the oil in a large pot set over a medium heat.
Add the peeled and chopped onion, season with a pinch of salt, and fry it until translucent.
Add the spices: oregano, cumin, chilli powder and pumpkin spice, peeled and chopped garlic, pumpkin, celery stalks and give it a good stir.
In goes the beef mince, use a wooden spoon to break it up until no longer lumpy and pink, and the juices released have evaporated.
Pour in the beef stock and chopped tomatoes, give everything a good mix, place a lid on the pot, and leave it to cook until most of the liquid has been absorbed, but the chili is still sloppy.
Add the cheese, season with salt and pepper, and garnish with chopped parsley.