Cut the asparagus into 1-inch lengths. Bring a large saucepan of salted water to a boil. Add the asparagus. Cook over high heat until tender. With a slotted spoon, transfer the asparagus to a plate.
Add the orzo to the boiling water, cook, stirring occasionally until al dente, about 10 minutes.
Meanwhile, In a medium skillet, melt the butter over medium-high heat. Reduce the heat to medium and cook until the butter begins to brown. Add the shrimp, season with salt and pepper and cook over moderate heat until pink and curled, about 1 minute per side.
With a slotted spoon, add the shrimp to the asparagus. Reserve the brown butter.
Drain the orzo, reserving 1/2 cup of the cooking water, then return the orzo to the saucepan and stir in the brown butter. Set the skillet over high heat and add the stock, scraping up any browned bits stuck to the bottom of the pan.
Pour the reserved cooking water into the orzo, cook over moderate heat, stirring until creamy, about 2 minutes.
Stir in the asparagus and shrimp and cook until heated through.
Remove from the heat. Stir in the parsley and the 1/2 cup of Parmesan. Season with salt and pepper. Transfer the risotto to bowls and serve with more Parmesan.