Heat the oil in a large pan, add the onion and garlic and fry gently for a couple of minutes. Add the peppers and reduce the heat.
While the above are cooking, gently fry the bacon in a frying pan for a couple of minutes until it starts to crisp up, then add the mince and heat until browned, stirring regularly to break up any lumps.
Once browned, drain off any excess fat and add the mince and bacon to the onions and peppers. Season with salt and pepper to taste.
Add the passata and mushrooms. Stir to combine, and heat gently for a couple of minutes.
Dissolve the stock cubes in the water and add to pan.
Add the chili powder, ketchup and cumin, stir well, then add the vinegar and Worcestershire sauce, stir to combine, and bring to the boil. Taste and correct seasoning if required. If using tinned tomatoes you may want to add a teaspoon of sugar to correct the acidity. Reduce the heat to low and simmer, stirring occasionally, until the mixture thickens, about 30 minutes.
Traditionally served on burger buns, but messy. Good on jacket potatoes.