Cottage Pie with Cheesy Mash - Irish Beef

Ingredients

• 2 tbsp olive oil
• 2 onions, finely diced
• 2 celery sticks, finely diced
• 2 carrots, finely diced
• 1 tsp soft fresh thyme leaves
• 2 bay leaves
• 500g (1lb 2 oz) minced beef (coarsely ground, if possible)
• 2 tsp plain flour
• 1 tsp tomato purée
• 1 tsp prepared English mustard
• 1 tbsp Worcestershire sauce
• 450ml (3/4 pint) beef stock
• 1kg (2 ¼b) potatoes, cut into chunks
• large knob of butter
• good splash milk
• 75g (3oz) Cheddar cheese, grated
• sea salt and freshly ground black pepper
• Ingredients
• Method