Preheat the oven to 160 ºC fan and spray a deep casserole dish (suitable for use on stove and oven) with low-calorie cooking spray.
Place over a medium heat, then add the onions and cook for 10 minutes — until soft and golden. Add the garlic, and continue to cook for 1-2 minutes.
Add the peppers and cook for 5 minutes. Then add the minced beef and cook for a further 4-5 minutes, until browned.
Add the chilli powder, smoky BBQ seasoning, paprika, and cumin. Stir everything in, and cook for 1-2 minutes.
Lower the heat and add the chopped tomatoes, tomato puree, kidney beans, balsamic vinegar, Worcestershire sauce (or Henderson's relish), sriracha sauce and beef stock. Stir well, then cover with a tight-fitting lid, and place in the oven.
Cook for 1 1/4 - 1 1/2 hours, checking occasionally, and stirring. If the chilli looks like it’s drying out, add a little more water. The chilli will be ready when it's rich and thick. Then serve!