In a small saucepan, warm the chicken broth over low heat and keep it at a bare simmer.
Heat the olive oil in a large skillet over medium-high heat; add the diced chicken and cook until golden and cooked through, then remove and set aside.
In the same skillet, add the sliced mushrooms and sauté until they release their moisture and turn a deep golden brown, then remove and set aside with the chicken.
Reduce heat to medium, add the minced shallot and garlic to the skillet, and sauté for 1-2 minutes until fragrant and translucent.
Add the Arborio rice to the skillet and toast for 2 minutes, stirring constantly until the edges of the grains are translucent.
Begin adding the warm broth one ladle at a time, stirring frequently and waiting for the liquid to be almost fully absorbed before adding the next ladle.
Continue this process for about 18-20 minutes until the rice is tender but still has a slight bite and the consistency is creamy.
Stir the cooked chicken, mushrooms, sea salt, black pepper, and fresh thyme back into the risotto.
Remove from heat and fold in the grated Parmesan cheese until fully melted and incorporated.
Serve immediately while the risotto is velvety and warm.