01 - Bring a medium saucepan of salted water to a boil. Add diced potatoes and cook for 5-6 minutes, until just tender. Drain well and set aside.
02 - Heat butter and olive oil in a large skillet over medium heat. Add onions and red bell pepper; sauté 3-4 minutes until softened.
03 - Add drained potatoes to the skillet. Cook, stirring occasionally, until potatoes start to brown, about 7-8 minutes.
04 - Stir in diced corned beef. Continue cooking, pressing mixture into an even layer, for 5-7 minutes until the hash is golden and crispy. Season with salt and pepper. Stir in chopped parsley.
05 - Fill a wide saucepan with about 2 inches of water. Bring to a gentle simmer and add vinegar.
06 - Crack each egg into a small cup. Create a gentle whirlpool in the simmering water and slide in eggs one at a time. Poach for 3-4 minutes until whites are set but yolks are runny. Remove with a slotted spoon and drain on paper towels.
07 - Divide the hash among four plates. Top each with a poached egg. Garnish with extra parsley and freshly ground black pepper.