Heat the oil in a pan and fry together the garlic, onion and chilli. Add in the beef mince, spices and season well with salt and pepper. Brown for a few minutes, then add in the beef stock pot and tomato concentrate and cook for 1 minute. Add in the polpa, cinnamon stick, Worcestershire sauce and a drop of water and cook down together for 10-15 minutes. When ready, discard the cinnamon stick and mix in the fresh coriander and Worcestershire sauce.  Meanwhile, make the sour cream by mixing together the single cream and juice ½ lime. Stir and place into the fridge to thicken. To serve, spoon the cooked rice into bowls with the chilli con carne sauce on top. Drizzle over the sour cream, dress with extra coriander leaves and serve a handful of the cheesy tortilla chips on the side.