Add the olive oil to a large pan, on medium heat
Add the bay leaf, onion, celery, garlic, thyme and carrots and cook until carrots and celery is soft.
Add the mince meat. Cook on high heat. Add the flour. Mix well.
Add the chilli powder, steak and chops seasoning and the tomato paste. Cook for a minute
Break up the stock cube and add it to the mince. Add the lamb stock.
Cook until gravy thickens, about 30 minutes. Season with more salt and add the pepper.
Preheat oven to 200 degrees Celsius.
Transfer the filling into an ovenproof dish, 30cm x 20cm. Spread mashed potatoes on top and use a fork to make some squiggles on top. Drizzle the melted butter over the mashed potatoes. This will give it that golden brown bits on top
If you adding cheese you can sprinkle some over. Bake in the oven for 25-30 minutes until its golden on top and the filling starts to bubble. Garnish with more fresh thyme
Stand for 5 minutes before serving