How to Make It
Preheat the oven to 375°. Spread the butter on the pumpernickel bread. Bake for about 4 minutes, until crisp. Let cool, then break the toast into 1/2-inch pieces.
In a skillet, heat the 2 tablespoons of oil. Add the onion and cook over moderate heat until softened, about 7 minutes. Add the capers and vinegar and cook, stirring, for 30 seconds. Remove from the heat. Stir in the parsley and season with salt and pepper.
Light a grill or heat a grill pan. Drizzle the asparagus with oil and season with salt and pepper. Grill over medium heat, turning, until lightly charred and crisp-tender, 5 minutes.
Meanwhile, bring a saucepan of water to a boil. Add the eggs and simmer over moderate heat for 4 1/2 minutes. Transfer the eggs to a bowl of ice water; keep the water simmering. Gently crack the eggs all over and carefully remove the shells, keeping the eggs whole.
Return the shelled eggs to the simmering water until heated through, 30 seconds. Arrange the asparagus on plates and top with the onion relish and the eggs. Season with salt and pepper. Scatter the pumpernickel crumbs on top and serve.