Fry the beef mince in batches until brown all over. (You shouldn't need any oil as fat will be released from the mince.)
As it cooks, spoon it out into a dish.
In the same pan, in the fat left in the pan, fry off the onions, carrots, celery, garlic and thyme gently for about 10 minutes until starting to soften.
Stir in the flour and mix well so it's disbursed through the vegetables.
Pour in the red wine (if using) and allow to bubble away for 5 minutes.
Add in the beef stock, Worcestershire sauce, tomato puree and plenty of salt and pepper.
Put the lid on and cook gently over a low heat for 30 minutes, stirring occasionally.
Preheat the oven to 180C.
Meanwhile, boil the sweet potatoes and white potatoes in a pan of boiling water for about 20 minutes until soft and tender.
Drain and mash well.
When the mince is cooked, transfer to one large or two smaller shallow dishes. Top with the mashed potatoes, sprinkle on the cheese.
Bake in the oven for about 20 minutes or until the cheese is bubbling.
Prep time: 10 minutes
Cook time: 1 hour 20 minutes
1 kg Minced Beef
200 g Onion
300 g Carrots
300 g Celery
4 Cloves Garlic
10 g Fresh thyme
4 tbsp Plain flour
250 ml Red wine
750 ml Beef stock
3 tbsp Worcestershire sauce
3 tbsp Tomato puree
Salt and pepper
2 kg Sweet potatoes
500 g White potatoes
100 g Cheddar cheese