Cube the chicken breast to approximately 2" cubes. This keeps it from having long strands when shredding. Season chicken with 1 Tbsp Salt, 1Tbsp pepper, 1 tsp garlic powder, 1 tsp onion powder and 1 Tbsp Italian seasoning.
Place seasoned chicken in crockpot and add the white wine. Cook on slow for 8 hours. Shred chicken using two forks and keeping the cooking liquid.
Preheat oven to 350 degrees
Prepare the squash by cutting it in half and removing the seeds. Rub each half with a teaspoon of olive oil making sure to coat all exposed flesh. (not the skin). Divide the seasonings on each half - 1/2 Tbsp salt, 1/2 Tbsp pepper, 1 tsp garlic powder, 1 tsp onion powder and 1/2 tsp cayenne pepper. Bake at 350 for one hour. (this can be done the day before and the squash can be kept in the fridge until you are ready to prepare the dish)
Let it cool and the shred the squash with a fork to create those beautiful strands.
It a large skillet, mix the broccoli, onions, the remaining salt and pepper and the chicken stock. Bring to a simmer. Cover the pan and simmer for 10 minutes. Remove the lid and simmer for 10 more minutes or until the liquid is reduced by at least half. Turn off the heat
While broccoli mixture is still hot, add the cream cheese. Let the mixture sit for a few minutes to help melt the cheese and then stir to combine.
In a very large mixing bowl combine the shredded chicken, the shredded squash, the broccoli mixture, the lemon zest and the cheddar cheese. Mix well. (do a taste test to see if you need more S and P!)
Place the mixture in a 9" by 13" casserole dish. Bake for 30 minutes at 350 degrees.