In a large casserole dish (I find a cast iron one best), heat the oil and gently fry the onion until soft.
Add the lamb and cook until browned off – stirring to break up the lumps.
Add the garlic, courgette, chilli and pepper and cook for 5 minutes.
Stir in the all the herbs and spices and simmer for 2 minutes.
Add the remaining ingredients, bring to the boil and them simmer for at least half an hour, but the longer the better.
Pre-heat the oven to 180’C
Cook the potatoes in boiling salty water for 15-20 minutes, until soft enough to mash.
Strain the potatoes and return to a low heat to get rid of any excess liquid.
Mash together with the butter and salt and pepper until smooth and fluffy.
Pour the lamb mix out into a suitable oven proof dish and pipe or spread the mash on top.
Sprinkle over the parmesan and a little black pepper and bake in the oven for 40 minutes, until lovely and crisp.
Serve with seasonal vegetables and enjoy!