Prepare the asparagus by trimming the woody ends. Slice the bottom halves into small pieces and top halves into 1-inch segments.

Bring 4 cups of chicken stock to a boil. Add the bottom asparagus pieces for 1 minute, then remove and puree with 1/4 to 1/3 cup stock until smooth. Keep the remaining stock warm.

Slice chicken breasts in half horizontally, season with salt and pepper. In a large skillet, heat 1.5 tablespoons of olive oil over high heat. Pan-fry the chicken for about 4 minutes per side, adding asparagus tips during the last 3 minutes. Remove both the chicken and asparagus and set aside.

In that same pan, reduce the heat to medium and add a heaped tablespoon of butter alongside another 1/2 tablespoon of olive oil. When the butter melts, add the onion and sauté for about 3 minutes until translucent.

Add the garlic and lemon zest for an additional 30 seconds.

Stir in the arborio rice, cooking for approximately 1 minute until it looks slightly transparent.

Gradually add the warm stock, one to two ladles at a time, stirring frequently. Wait until most of the liquid is absorbed before adding more; total cooking time is around 15 minutes.

Once the rice is nearly done, stir in the Parmesan and asparagus puree. Taste and adjust with more lemon juice, salt, and pepper as needed. Turn off the heat.

Arrange the sliced chicken and asparagus tips over the risotto, garnishing with extra Parmesan and herbs if using.