Filling:

1. In a large deep pan heat a little olive oil and butter. Sauté the onions and carrots together, until the onions start to soften. Add the minced lamb and cook until browned.
2. Add the crushed garlic and sauté for just 1 minute, until fragrant. Turn down the heat to low and add the flour. Stir until well combined.
3. Add the herbs, tomato paste, Worcestershire sauce and vegetable stock. Bring to boil and simmer covered for 15 minutes, stirring occasionally.
4. Add the sweetcorn and peas. Stir through and remove from stove.
5. Pour the filling into a casserole dish and spread evenly.
6. Top with mashed potatoes and bake in oven 190C/375F until potatoes are crunchy and golden.

Mashed Potatoes:

1. Peel and cook potatoes in salted boiling water. Drain and add enough butter, canned and fresh milk to make it creamy but not too soft. Stir in the cheese and egg yolks.
2. Spread a thin layer of mash potatoes over the lamb filling before piping (this will seal the gravy from seaping up in between the piped potatoes).
3. Enjoy!