Step 1: Prepare the Broth

1. In a saucepan, heat the chicken broth over low heat to keep it warm throughout the cooking process.

Step 2: Cook the Chicken

1. In a large skillet or saucepan, heat 1 tablespoon of olive oil over medium heat.
2. Add the diced chicken breast, season with salt and pepper, and cook until browned and cooked through (about 5-7 minutes). Remove the chicken from the pan and set aside.

Step 3: Sauté the Vegetables

1. In the same pan, add the remaining tablespoon of olive oil. Add the chopped onion and sauté until translucent (about 3-4 minutes).
2. Add the minced garlic and sliced mushrooms, cooking until the mushrooms are tender and have released their moisture (about 5 minutes).

Step 4: Add the Rice

1. Stir in the Arborio rice and cook for about 1-2 minutes, allowing it to toast slightly and absorb the flavors.

Step 5: Add Wine (Optional)

1. If using, pour in the white wine and stir until it is mostly absorbed by the rice.

Step 6: Gradually Add Broth

1. Begin adding the warm chicken broth, one ladle at a time, stirring frequently. Allow the rice to absorb most of the liquid before adding more broth.
2. Continue this process for about 18-20 minutes, or until the rice is creamy and al dente. You may not need all the broth.

Step 7: Finish the Risotto

1. Once the rice is cooked, stir in the cooked chicken, Parmesan cheese, and butter. Mix until creamy and well combined. Adjust seasoning with salt and pepper as needed.

Step 8: Serve

1. Serve the risotto warm, garnished with fresh parsley and additional Parmesan cheese if desired.