Preheat the oven to 180 degrees celcius.

Heat the olive oil in a heavy based saucepan and cook the onion, celery, carrot and zucchini.

Once softened and taking on just a bit of brown, push to one side of the pan and add the mince. Leave the mince to sear and brown on one side then use a spoon to break up the mince and mix through the vegetables. Cook until the mince has browned.

Mix through the kale or spinach.

Add then plain flour, crumbled beef stock cube, tomato paste and tomato sauce. Mix very well and then add the water. Adjust the amount of water according to how saucy you'd like the mixture.

Turn off the heat and add the frozen peas.

Pour the mixture into a 2 litre casserole dish.

Peel and cut up the potatoes and add to a pot of cold water. Add the salt too

Cook on medium high heat until the potatoes are cooked and completely sift. Use a fork to make sure the middle of the potato pieces aren't hard.

Once cooked, drain the water from the potato and add butter and milk straight away. Allow the potato, butter and milk to sit for a few minutes.

Using a potato masher, mash the potato, then using a fast stirring motion, whip the potato. It's an arm work out!!

Using a large spoon scoop the potato onto the top beef mixture and spread evenly but make sure the top is not smooth. The craggily uneven potato will crisp up nicely in the oven.

Sprinkle over the cheese and place in the oven for 25 minutes or until the cheese has browned up nicely.

You may need to turn on the fan grill to give it a little helping hand.