Chop the shallots and mince the garlic, cube the chicken breasts into bite-sized pieces. Cut mushrooms in half and leave the small ones whole. Take the thyme leaves off their stems and place all ingredients in front of you until needed.
Heat 1 tbsp of olive oil in a large and deep pan or a wide pot if you don't have a deep pan. Add shallots and sauté over low heat for 1 minute, then add cut up chicken breasts with a pinch of salt and sauté over medium heat until just sealed but not cooked all the way through. Then add mushrooms and cook while stirring for 2-3 minutes longer, then add minced garlic and give everything a quick stir.
Add arborio rice and sauté while stirring until all rice is even coated with the olive oil for about 1 minute, then pour in white wine and start scraping down the bottom of the pan to release all the brown bit into the broth, let it simmer over low heat for 2-3 minutes. Then add ¼ of the water and thyme, stir and let it simmer for a few minutes over medium heat. The water should be just above the rice when you first add it. Once you see the water going down add a bit more and stir. Repeat until all water is gone and the rice is cooked but still slightly chewy. Give it a quick stir every time you add more water or stock if using.
Once the rice is cooked and the risotto is nice and creamy consistency, stir in grated Parmesan cheese, stir until melted, then taste it and season with salt. Cover with a lid and let it stand for 5 minutes. Serve with more grated Parmesan and black pepper.
Notes
If your rice is cooked but the risotto looks a bit dry, add ¼ cup of water or stock and stir over very low heat.