- STEP 1
peel and cube both the Yams and everyday potatoes into generous chunks, and place into a large cooking pot that has a lid. Bring a full kettle of water to the boil and pour over the potatoes. Boil the potatoes for 10 minutes on full heat, with lid placed on top of the pan - ensuring that the water covers the potatoes, and not filled right to the top of pan where water can escape and overflow.
- STEP 2
After boiling for 10 minutes, turn heat down to a moderate temperature: (Gas mark 3) and simmer the potatoes for a further 15 minutes until soft, rather than crumbly - check with a fork or knife, as they need to be soft enough for mashing, yet not overly cooked so that they fal apart too easily.
- STEP 3
Take potatoes off the heat and drain well. Add the margarine or butter, and milk together, then mash with a firm masher. Lastly, add the whole tin of Corned Beef and mix well into the potatoes, which should form a solid mix.
- STEP 4
Empty the contents of the whole pan into a large oven dish, or one that is fairly deep. Flatten down the potato mix and roughly fork peaks on top of it. Chop two large Tomatoes and place on top - spreading evenly. Place into the oven on a moderate heat for 30-35 minutes (Gas mark 150 degrees).
Serve hot from oven and garnish with your favourite sauce!