450g(ish) of potatoes cooked and mashed with a little butter (if you like).

For the filling, fry 150g of mushrooms fried until golden, add 15g of Worcestershire sauce until it evaporates. Add two cloves of crushed/grated garlic with a few finely chopped sundried tomatoes (you don't need to use them but I think they're great) and fry for around a minute. Then around 75ml water with 200g (ish) of passata and a tin of green lentils (I drain and rinse), season and cook down until thickened. I add one of the jelly red wine stock things you can get ... again adds more flavour, but season after adding that.

I cook the above for about 10 mins and add a dash more passata/water if it dries out early.

Once reduced add the base into a bake proof dish, add the mash on top.

The topping is around 150g of sour cream, 40g of cheddar and a tsp of Dejon mustard. Mix together and then spread over the mash. 20 mins in the oven at around 220c.

Corn beef bash is something I've not had in years! That's going on my shopping list for next week!