Preheat oven to 160°C (320°F). Heat oil in a large heavy-based pot and brown the beef on all sides. Remove and set aside.
Add onions and mushrooms to the pot. Stir for 4-5 minutes, and add garlic. Cook until softened. Add oil, vinegars and mushrooms to pot. Stir to combine.
Return beef to pot. Add stock, wine, sauce and tomato paste. Stir to combine. Add thyme sprigs and bring to the boil.
Cover the pot. Place in oven. Cook HIGH TEMP for 3 hours and press. START when cooking is complete. Remove beef and mushrooms and press. START. Do not close the lid.
Remove from oven. INCREASE TEMP. If TEMP is high, set cooking time for 10 minutes and press START. Do not close the lid.
Reduce sauce two, reduces and thickened. Serve with sweet potato mash.
