In a small (3- to 4-quart [2.8- to 3.8-L]) pot, bring to a boil a quart of water.
Add 1 teaspoon salt and asparagus and cook for 2 minutes.
Drain the asparagus and shock it immediately under cold running water.
Cut the cooked asparagus into bite-sized pieces and set aside.
In a medium (8- to 12-quart [7.6- to 11.4-L]) pot, heat up stock over medium heat.
In 11-inch pan, warm up the olive oil and onions over low heat and cook until the onions are soft, about 10 minutes, stirring occasionally to prevent the onions from burning.
Add the rice, turn up heat to medium and toast the rice for a minute or two, stirring so the rice does not stick to the bottom of the pan.
Add the wine, turn up heat to medium-high and cook until the wine reduces by about 1/3.
Start adding the hot stock one ladle at a time, stirring the risotto after each addition. Add ½ teaspoons of salt.
After 14-15 minutes, when the rice is al dente, take the risotto off the heat, add the butter and the cooked asparagus and stir well.
Adjust seasoning to taste and serve hot.