2 tablespoons unsalted butter, at room temperature
2 tablespoons white miso paste
1/2 teaspoon sherry vinegar
1 bunch thin green asparagus, bottom ends trimmed (about 1 pound)
2 teaspoons olive oil
2 large poached eggs
Heat the oven to 475°F and arrange a rack in the middle. Combine butter, miso paste, and sherry vinegar in a small bowl and stir until smooth. (Mixture will be thick.) Set aside.
Place asparagus in a single layer on a large, rimmed baking sheet, coat with olive oil, and season well with salt and freshly ground black pepper. Place asparagus in the oven and roast until it is knife tender and lightly blackened, 12 to 15 minutes.
To serve, place miso butter on plate, top with roasted asparagus, and a poached egg.