Heat some oil in a large cooking pan over a medium heat. Dip the chicken pieces into flour. And fry till the chicken is golden brown. Remove and set aside.
In the same pan, add the butter and scrape the pan to get all the flavour off the bottom and moving. Add the mushrooms and sauté till golden. Remove the mushrooms and set aside.
Turn the heat to high and add the white vinegar to deglaze the pan Next add the can of tomatoes, mixed herbs and garlic powder. Mix well. Add salt and pepper to taste. Add the juice of one lemon and then cut the leftover rind and place it in the sauce. Mix the sauce well and simmer for 5 mins.
Add the chicken back into the pan. Sprinkle the drained olives, feta and sundried tomatoes on top. Cover and simmer for 15 mins. Check for seasoning and add more if you need to. Flip the chicken over and simmer for another 15 mins, with the lid on.
Add the cooked mushrooms on the top, cover it with the lid, and simmer for 5 mins.
Then leave to cook with the lid off for about 5 mins to let some of the steam out.
Garnish with chopped parsley and serve