In a skillet, melt the butter over medium-high heat. Add the artichoke hearts and a pinch of salt and pepper and cook, stirring, until just warmed through, 1 to 2 minutes. Remove from the heat and cover to keep warm.
Into a large saute pan or deep skillet, pour about 2 inches of cold water and the vinegar. Bring to a simmer over high heat, then reduce the heat so that the surface of the water barely shimmers.
Break the eggs into individual saucers, then gently slide them 1 at a time into the water and with a large spoon, lift the whites over the yolks. Repeat the lifting once or twice to completely enclose each yolk. Poach until the whites are set and the yolks feel soft when gently touched, 3 to 4 minutes.
Remove the eggs with a slotted spoon, and place on a large plate.
Arrange the warm artichoke hearts on each of 4 plates and top with the spinach. Lay 1 egg on top of each bed of spinach and drizzle with warm Hollandaise sauce. Garnish with the chopped prosciutto, Essence, and chives and serve immediately.
Yield: 4 appetizer servings