The inspiration for this recipe came from a magazine I was reading while waiting for an appointment.  I did not have time to write it down, so have gone with my own, sometimes not always reliable memory.  I do recall the original recipe used a Bechamel sauce, which I did not use here.  This makes enough to feed at least 6 big yummy portions. I also loved the combination of cauliflower and yukon gold mashed potatoes for a topping.  It turned out to be tastier than I thought it would.  The different layers of flavors really came through...a chicken casserole I will make again and again.  You can never have too many chicken casserole dishes right?
I made this in the morning so it was ready to reheat for dinner that night.
4 cups cauliflower, coarsely chopped
2 1/2 cups yukon gold potatoes, peeled and diced
1 large Tblsp. butter
2 Tblsp. plain organic yogurt
1 green onion, finely chopped
generous 1/2 cup Parmesan cheese
2 large skinless, boneless chicken breasts, cubed
Extra Virgin Olive Oil
Herbamare Seasoning
1 onion, chopped
2 garlic cloves, minced
1 celery stalk, cut in half and diced
2 carrots diced
2 cups butternut squash, peeled, and cut into 1 inch cubes
22 green beans, ends trimmed and cut into 1 inch pieces
2 cups chicken stock
2 Tblsp. Balsamic Vinegar
3 tsp. fresh minced sage, 1 bay leaf
small handful of minced fresh Italian flat leaf parsley
3 crimini mushrooms, roughly chopped
2 1/2 cups grated cheddar cheese - divided
salt and fresh cracked pepper
corn starch and chicken stock to make a slurry
Add your chopped cauliflower and potatoes to a pot of salted boiling water.  Cook about 15 minutes or until tender, then drain well.  Add butter, yogurt, parmesan cheese and green onion, mashing well, then set aside.
Heat up a saute pan on medium high heat with a good drizzle of olive oil.  Add the chicken pieces to the pan, and season well with Herbamare seasoning.  Saute about 7 minutes until the chicken is no longer pink, transfer to a bowl and set aside.  To the pan add in the mushrooms sauteing - turn down to medium heat.  Once the mushrooms are a light golden color, add in the celery, carrots, onions and garlic.  Saute for about 5 minutes.
Add the balsamic vinegar scraping up any brown bits.  Then add in the chicken stock, fresh sage, bay leaf and season with salt and pepper.  Simmer lid on slightly cracked for 7 minutes.  Add in the squash and continue to simmer about 5 minutes, or until the vegetables are tender.  Then add the green beans and simmer for 3 more minutes.
Take the lid off, and reduce - about 5 minutes.  Thicken with the cornstarch slurry, and check for seasonings.  Add in the Italian Flat Leaf Parsley and chicken, stirring to combine.  Transfer to a casserole dish.
Sprinkle 1/2 of the cheddar cheese over top.
Spoon over the cauliflower mashed potatoes, and add remaining cheese on top.  Bake 350 degrees for 1 hour if made in the morning and reheating or bake at 375 degrees for about 25-30 minutes.  Let rest 5 minutes, then serve.