1) Preheat oven to 230C/fan 210C/gas 8, Put a baking tray in to heat up. 2) For the cornbread, Mix together the flour, cornmeal, some salt and baking powder. 3) Make a well in the centre and add the milk and egg. Mix together from the centre outwards, incorporating the dry ingredients into the wet gradually to create a dough-like paste. Add the melted butter last. 4) Remove the tray from the oven and place the dough in. Cook for about 15 minutes until golden brown. 5) Remove from the oven, allow to cool slightly. Turn out, cut into slices. 6) Meanwhile, for the corned beef hash, Bring a saucepan of water to the boil. Add the potatoes and turn down to a simmer. Cook for 10 minutes or until tender. Drain and set aside. 6) Heat a frying pan until hot. Add one tablespoon of the olive oil, the onion and garlic and fry for two to three minutes. 7) Add the potatoes and corned beef and fry for a minute more. 8) Put the mixture into a shallow dish, then place under the grill for 3 - 4 minutes, until crusty. 9) To poach the eggs, bring a pan of water to the boil, add the vinegar and whirl the water around. 10) Crack an egg into a tea cup. Pour the egg into the pan and simmer for two minutes, or until cooked to your liking. Remove from the pan and drain. Repeat with the rest of the eggs. 11) Remove the hash from the grill and dish onto 4 plates. Top each with a poached egg and serve with a slice of cornbread.