Remove the skin from the chicken.
If you're using an Instant Pot, set to Sauté and spray with a decent amount of low calorie cooking spray. If you're using a regular slow cooker, spray a frying pan with some low calorie cooking spray.
Add the chopped onion and garlic to the pot and cook for 5 minutes, or until the onions start to soften. If you're using a regular slow cooker, sauté the onion and garlic in a frying pan. Then tip them into the slow cooker.
Add the sliced peppers, sliced carrots, chopped tomatoes, tomato puree and red wine vinegar. Stir well.
Dissolve the stock cube in a little hot water, then add that to the slow cooker.
Add the thyme, parsley, basil, oregano and balsamic vinegar. Season with a good pinch of salt and pepper.
Stir, then add the chicken portions.
Cook for 4 hours on medium or 6-8 hours on low.
30-60 minutes or so before the end of cooking time, throw in the mushrooms and cherry tomatoes, stir.
When the vegetables are soft and the chicken is cooked through and it falls off the bone, check the seasoning. Add some more salt and pepper if necessary.
Serve with whatever takes your fancy. Pasta, mash, wedges, or just plenty of veg!