01 - Heat olive oil in a large heavy-bottomed saucepan or Dutch oven over medium heat. Season diced chicken generously with salt and pepper. Add to the hot pan and cook, stirring occasionally, until browned on all sides and cooked through, approximately 5 to 6 minutes. Transfer chicken to a plate and reserve.
02 - In the same pan, add 1 tablespoon butter. Reduce heat to medium-low and add diced onion. Sauté until translucent and softened, about 3 minutes. Add minced garlic and cook, stirring constantly, for 1 minute until fragrant but not browned.
03 - Increase heat to medium. Add Arborio rice to the pan and cook, stirring frequently, for 2 minutes until the grains are lightly toasted and the edges become translucent.
04 - Pour in white wine and stir continuously until completely absorbed by the rice, approximately 1 to 2 minutes. The alcohol should evaporate, leaving a subtle aromatic base.
05 - Add warm chicken broth one ladleful at a time (approximately ½ cup per addition), stirring frequently. Wait until each addition is almost completely absorbed before adding the next. Continue this process for approximately 15 minutes until the rice begins to soften.
06 - Stir in asparagus pieces and continue adding broth gradually, stirring frequently. Cook for an additional 10 minutes until the rice is creamy and al dente with a slight bite at the center, and the asparagus is tender-crisp.
07 - Return reserved chicken to the pan. Remove from heat and stir in remaining butter, Parmesan cheese, and lemon zest until thoroughly combined and creamy. Season to taste with salt and pepper. Cover and let rest for 2 minutes to allow flavors to meld.
08 - Divide risotto among warmed bowls. Garnish with fresh parsley and additional grated Parmesan cheese if desired. Serve immediately while hot and creamy.