Preheat the oven to 350 degrees F.

Spray a 9x13" dish with cooking spray.

Begin by preparing the veggies. Cook broccoli in the microwave according to package directions and drain once done; set aside. Wash mushrooms and dry well and dice your onions.

In a large skillet, add the olive oil and set to medium heat. Add the mushrooms and onions and cook for 5-6 minutes, or until mushrooms are tender. Drain any liquid if needed.

Sprinkle the flour over the mushrooms and stir until the flour is evenly dispersed. Then add the milk and bring the mixture to a boil, stirring continuously for 4-5 minutes, or until the mixture has thickened. Remove from heat.

In a very large bowl, add the yogurt, mayonnaise, ranch seasoning mix, salt and pepper. Mix to combine. Then add the mushroom mixture, broccoli, and chicken. Stir until everything is mixed together well, then add it to the prepared dish and sprinkle evenly with the cheese.

Bake for 15-20 minutes or until it becomes bubbly around the edges.

Let cool for few minutes then dig in and enjoy!