01 - Heat olive oil in a large heavy saucepan over medium heat. Season diced chicken with salt and pepper, then cook until browned and cooked through, about 5–6 minutes. Remove chicken and set aside.
02 - Add 1 tablespoon butter to the same pan. Sauté onion until translucent, about 3 minutes. Stir in garlic and cook for 1 minute until fragrant.
03 - Add Arborio rice and cook, stirring constantly, for 2 minutes until grains are lightly toasted and edges become translucent.
04 - Pour in white wine, stirring continuously until completely absorbed by the rice.
05 - Add hot chicken stock one ladleful at a time, stirring frequently. Allow each addition to be fully absorbed before adding more. Continue for approximately 15 minutes.
06 - Stir in asparagus pieces and continue adding stock gradually. Cook for another 10 minutes until rice is creamy and al dente with a slight bite, and asparagus is just tender.
07 - Return cooked chicken to the pan. Stir in remaining butter, Parmesan cheese, and lemon zest until melted and combined. Adjust seasoning with salt and pepper. Remove from heat, cover, and let rest for 2 minutes. Garnish with parsley and extra Parmesan if desired. Serve immediately.