Heat the oil and butter in a large heavy-based saucepan over a medium-high heat. Add the onion and carrot, reduce the heat a little and sweat for 5 minutes. Add the garlic and cook for a further 1-2 mintues.
Deglaze the pan with the cider and stir well to remove any residue that has collected. Add the sausages and brown for 4-5 minutes and then add the tomatoes. Cover with the beef stock and add the thyme sprigs. Simmer for 15 minutes until the sausages are cooked.
Serve once the sausages are cooked with no pink showing.
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.