In a large saucepan, add the vegetable stock and heat on medium until it is steaming hot, but not boiling and not yet simmering. Turn down the heat slightly to maintain the heat of the stock.
Add a water to a large skillet with a high rim and heat until the water is boiling. Thoroughly wash the asparagus and trim the tough ends. Add the asparagus the skillet and blanch until it is a bright green.
Discard all but one cup of the water. Add the reserved water to the vegetable stock.
Allow the asparagus to cool until you can touch it. Trim the tender tops and place in a small bowl. Cover with some of the vegetable stock until the asparagus is mostly covered with the liquid and set aside.
Chop the remaining asparagus stalks into one inch pieces. If you are using thicker asparagus, also cut the pieces in half. Set aside.
Add the extra virgin olive oil and two tablespoons of the butter to the skillet and heat on medium high until the butter is melted and the mixture is hot.
Add the finely chopped onion to the skillet and cook, stirring occasionally, until you can smell the onions and they turn transparent.
Add the risotto rice to the onions and cook for about two minutes, stirring occasionally. You want to toast the rice slightly. Add the chopped asparagus stalks (not the tips) to the rice. Cook for another minute to heat the asparagus.
Add the wine and half a cup of the vegetable stock to the rice and cook until the liquid is completely absorbed by the rice. Stir the mixture as you cook.
As soon as the wine and stock is absorbed, add another cup of the vegetable stock. Stir and cook until the stock is again absorbed by the rice. Keep an eye on how quickly the liquid is absorbed by the rice. It shouldn't sizzle and evaporate right away, but it shouldn't take more than a minute or two for the rice to absorb the liquid. Adjust the temperature of your stove as needed.
Continue the process of adding a cup of stock and cooking until the liquid is absorbed. You will begin to notice the rice thickening and you will need to use a bit more effort to stir the mixture. Continue to cook, adding more of the stock one cup at a time. The rice should be tender, but not liquidy. It shouldn't clump together either. It should be thick, but you can still easily run a wooden spoon through the mixture. The process should take roughly 45 minutes to reach this consistency and you may not need all of the stock.
Once you've reached the desired consistency, add the remaining butter and stir it in well.
Add most of the Parmesan to the rice and stir it in. Season with salt and pepper to taste. Top with the asparagus tips and gently stir them in. Turn off the heat and serve immediately.