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 - Meanwhile, 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.