Preheat oven to 160ºC. Brush the beef roast with a little oil and season well with salt and pepper. Mix together the garlic, thyme and olive oil. Rub over the top of the beef.
Place beef into roasting dish with the onions and the half bunch thyme. Pour over the balsamic vinegar and red wine. Roast for 75 minutes for rare, 90 minutes for medium and 105 minutes for well done. For ease and accuracy use a meat thermometer.
Remove beef from oven, loosely cover with foil and rest for 20 minutes. Place the onions in a serving dish.
Add the brown sugar to the roasting dish, place on cooktop and stir to dissolve over a low heat. Add the butter and stir until just melted. Strain liquid through a fine sieve. Slice the beef and serve with the red wine juice, onions, roasted potatoes and steamed green vegetables.
Judging your roast’s degree of doneness using a meat thermometer. The internal temperature of the meat should be: Rare – 55-60ºC, Medium – 65-70ºC, Well done – 75ºC.
You can also use tongs to test the roast’s doneness. Gently prod or squeeze the roast – rare is very soft, medium rare is soft, medium is springy but soft, medium well is firm and well done is very firm.
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