Heat a dash of oil in a heavy-based saucepan over a medium-high heat and add the beef mince.

Brown mince, stirring with a wooden spoon to break up the meat, then transfer to a bowl.

Add another dash of oil to the saucepan and add the onion, carrot, celery and garlic and cook until they begin to soften, about 5 minutes.

Return mince to the saucepan.

Add the mushrooms, tomatoes, tomato paste, stock and thyme.

Bring to the boil, then reduce heat to low, cover and simmer mince for 45 minutes.

Stir mince from time to time and taste for seasoning.

Remove lid towards the end of the cooking time if you need to thicken the mince a little.