Season the chicken breast with half of the sea salt and black pepper.
In a small saucepan, bring the chicken bone broth to a low simmer.
Heat the olive oil in a skillet over medium heat and sear the chicken breast until cooked through, then set aside to rest.
In the same skillet, sauté the diced onion and sliced mushrooms until the mushrooms are browned and the onion is translucent.
Add the minced garlic and Arborio rice to the skillet, toasting the rice for 1 minute until the edges are slightly clear.
Add the simmering bone broth one ladle at a time, stirring constantly and allowing the liquid to be absorbed before adding more.
Continue this process until the rice is tender and creamy, which should take about 15-20 minutes.
Stir in the remaining salt, pepper, fresh thyme, and parmesan cheese.
Slice the chicken breast and serve it over the warm mushroom risotto.