Slice the onions. Heat olive oil and butter in a heavy bottomed pan, and fry onions till reduced, translucent and beginning to caramelise.

In a separate pan, boil potatoes. Drain water and mash potatoes with butter, cheese, pepper and thyme. Add salt to taste.

Prepare your minced mutton by mixing thoroughly with ginger, garlic, salt, paprika, nutmeg, black pepper and optionally chicken or meat seasoning and keep aside

In a mixer-grinder, put in tomatoes, green chillies and basil leaves, along with the fried onions. Grind until smooth paste

Return the tomato-onion paste to the heavy-bottommed pan and bring to a boil. Pour in mince mixture and stir till well assimmilated. Cover and simmer till meat releases its juices. Cook thoroughly till water is reduced and mince is tender. (I use a pressure cooker)

Transfer cooked mince to an oven-proof casserole. If necessary, mash mince with a fork to break down any clumps.

Layer the mashed potatoes on top of the mince, and grate more cheese if you like. Add a few dabs of butter

Cover the casserole and bake in the oven at 220 Celsius for 20 minutes.

Finish off under the grill for 15 minutes or until surface is golden and crusty

Ideally, let it rest for 2 hours before serving. Enjoy!