Fry the hash: Heat the oil and butter in a nonstick skillet over medium heat, add the onion, and cook until soft, about 5 minutes. Add the corned beef, vegetables,and chives; cook until the bottom is brown and crisp, about 5 to 10 minutes.
Poach the eggs: Meanwhile, fill a large skillet with water, bring it to a boil, and add the vinegar and a large pinch of salt. Reduce the heat until the water is just barely bubbling. Crack each egg into a small bowl and carefully slide the egg into the water. Cook until the eggs are set, about 3 1/2 to 4 minutes. Remove the eggs with a slotted spoon and dab the bottom with paper towels to dry them off.
Serve: Place 1/4 of the hash onto a warm plate or shallow bowl. Top with a poached egg and a couple of tablespoons of hollandaise; garnish with chives.
Meanwhile, make the Herb Butter by combining the soft butter and herbs together; season with some salt and pepper.
To serve, spread some Herb Butter in the bottom of a bowl. Add the hot vegetables and dot with more Herb Butter. Moisten with some of the cooking liquid and serve.
Yield: 6 to 8 servings
Prep Time: 20 minutes
Cook Time: 30 minutes
Ease of preparation: easy