Add half the oil to a large skillet set over medium high heat. Stir in the mushrooms and cook, stirring often, for 5 minutes until they've shrunk to half the original size and have browned some. Transfer them to a waiting plate.
3 tbsp extra virgin olive oil, 8 oz sliced baby bella mushrooms
Add the rest of the oil to the skillet along with the onions and saute them, stirring often, for 5 minutes or until softened.
1 yellow onion
Reduce the heat and add the zucchini to the pot and cook for 2-3 minutes, just until softened a bit.
1 medium zucchini
Add the mushrooms back to the pot along with the chicken broth. Whisk the cornstarch into the milk until evenly combined, then pour the slurry into the skillet and stir just until thickened some.
1 cup chicken broth, 1 cup milk, 2 tbsp cornstarch
Add the chicken, cheese, and garlic to the pot and stir together to evenly combine. Then add the rice, stirring again until evenly combined.
2-3 large chicken breasts, 2 1/2 cups steamed white rice, 1/2 cup grated parmesan cheese, 2 tsp garlic powder, salt & pepper
Serve warm with chopped parsley leaves and extra cheese for garnishes.
2 tbsp chopped parsley