Start by cutting the chicken breast into bite-sized pieces. Dice the onion, mince the garlic, and slice your mushrooms. Having everything ready before you start cooking makes the process smooth and stress-free.
Heat 2 tablespoons of olive oil in your skillet over medium-high heat. Add the chicken pieces and season with salt and pepper. Cook until the chicken is browned on all sides but not fully cooked through, about 4-5 minutes. Remove the chicken from the pan and set aside.
In the same pan, add the diced onion and sauté until translucent, about 3 minutes. Add the minced garlic and cook for 30 seconds until fragrant. Toss in the sliced mushrooms and dried thyme, cooking until the mushrooms release their moisture and start to brown, about 5 minutes.
Add the Arborio rice to the pan, stirring to coat it with the mushroom and onion mixture. Toast the rice for about 2 minutes; this step helps develop flavor and ensures the grains stay separate.
Pour in 2 cups of chicken broth and stir everything together. Return the chicken pieces to the pan. Bring the mixture to a gentle boil, then reduce heat to low, cover with a lid, and let it simmer for 15-18 minutes until the rice is tender and the liquid is mostly absorbed.
Once the rice is cooked, stir in 1 cup of heavy cream. Cook uncovered for another 3-5 minutes, allowing the sauce to thicken and become luxuriously creamy. Adjust seasoning with salt and pepper as needed.
Sprinkle chopped parsley over the top for a fresh pop of color and flavor. Serve immediately, spooning generous portions onto plates or bowls.