Melt one tablespoon of the butter in a large saucepan over medium heat. Add asparagus; cook and stir until bright green and crisp-tender, 3 to 4 minutes. Remove from pan.
To the same saucepan add remaining tablespoon of butter, leeks and salt; cook and stir until leeks are tender, 5-6 minutes.
Add rice to leeks; cook and stir 2 to 3 minutes, until rice is very shiny. Raise to medium-high heat and add wine. Bring to boil, stirring until wine is nearly absorbed.
Reduce heat to medium-low and begin to add simmering stock, one ladleful at a time, stirring often until liquid is nearly absorbed before adding the next. Stir risotto often during this process to keep it from sticking to the bottom of the saucepan.
Continue to cook the risotto, adding a ladleful or two at a time for 30 to 35 minutes, until the rice is nearly tender but still a bit firm in the middle.
Stir in asparagus and a bit more stock. When stock has absorbed, stir in cheese and a little more stock so that the risotto is creamy (neither runny nor stiff). Season to taste with salt and pepper.
Sprinkle with parsley and parmesan cheese if you like; serve.