Heat a skillet over medium–high heat. Spray the pan with nonstick cooking spray. Sprinkle the pepper over the short ribs. Sear the ribs in batches for two to three minutes on each side, until browned.

Preheat the oven to 350 degrees Fahrenheit.

Place the ribs in a large baking pan. Add garlic, onions, diced plum tomatoes, baby bella mushrooms, and parsley to the pan.

In a mixing bowl, combine red wine vinegar, tomato paste, brown sugar, salt, pepper, and cayenne pepper. Pour over the meat and vegetables. Then pour the vegetable stock over just to cover.

Cover pan and bake for two and a half hours until meat is very tender. Uncover and bake an additional half hour.