Preheat oven to 350º F. Spray an 8-inch square casserole dish with cooking spray. Cook broccoli in microwave according to directions; set aside.

Heat olive oil over medium-high heat, add chicken and cook for about 10 mins in oven-ready deep pan.

In the meantime, steam cut up broccoli in pan with small amount of water.

Add onion and mushrooms to chicken and saute for about 5 mins. Add steamed broccoli back in.

Add flour, stir to combine and cook for 1 min. Add milk and cook for 2 mins.

Sprinkle flour over chicken and mushroom mixture and stir constantly, cooking for one minute. Stir in milk. Bring to a boil and cook for 3 minutes, or until thick and bubbly.

Add yogurt, salt and pepper; stirring lightly to combine.

Sprinkle top with cheese and bake for 20 minutes, or until cheese melts and bubbles around the edges.

Serve and enjoy!