In a medium saucepan, bring the stock to a boil. Add the asparagus spears to blanch for 2-5 minutes. Remove the asparagus and place in an ice bath. Remove from both once cooled and set aside. Keep the stock warm over a low heat.
In a large saucepan, melt 2 tablespoons over medium-high heat. Add the onion and cook until softened, about 3 minutes.
Add the rice and stir to coat with butter. Toast the rice, stirring constantly for about 3 minutes.
Add the wine, and continue stirring until most is absorbed.
Add 1/2 cup of warm stock, continuously stirring until all absorbed. Continue with the remaining stock, 1/2 cup at a time and allowing each addition to be absorbed. Continue until rice is tender to the bite and the mixture is creamy (about 20 to 25 minutes).
Remove from heat, stir in the cheese, salt and pepper.
Cut up asparagus into bit size pieces, stir into the risotto.