Heat butter and oil in a large iron skillet; add onion and pepper and saute until soft, about 5 minutes. Add thyme, corned beef, potatoes, beets, and salt and pepper, to taste. Spread in a layer and cook over medium-high heat until potatoes begin to crisp on bottom, about 10 minutes (lift with a spatula to check). If desired, place a lid or metal plate that is slightly smaller in diameter than the skillet over the hash to tamp it down and make it extra-crisp.

Meanwhile, poach 1 or 2 eggs per serving until done to your liking. Spoon hash onto plates and top each portion with eggs, sprinkle with parsley, and serve with hollandaise, if desired.

In a bowl fitted into a saucepan with barely simmering water, whisk the yolks with the lemon juice until light and frothy. Whisk in the butter in 2-tablespoon increments. The sauce will seem thin at first, but continue to whisk until the sauce thickens. Be careful not to overcook because the eggs will scramble. When sauce is thick, remove from heat and stir in remaining ingredients. Serve immediately.

Yield: 2 cups