Heat a large skillet over medium heat and add the bacon pieces to it. Allow the bacon fat to render and the bacon bits to brown. When the bacon is crispy, carefully remove the pieces from the pan but keep any bacon fat in the pan.
In a small bowl, combine the dill, onion, garlic, salt and pepper.
Add the chicken breast to the pan. Sprinkle half of the dill mixture on top of the chicken. Brown the chicken for 2 minutes on each side. Add the cauliflower to the pan and saute until the chicken reaches an internal temperature of 165 degrees Fahrenheit and the cauliflower is soft. Add the browned bacon bits, remaining dill spice mixture, lemon juice, apple cider vinegar, half of the parsley, chives and chicken broth and mix together. You can keep the chicken chunks whole or shred them with two forks. Set aside.
Boil a pot of water and add the chickpea pasta. Boil for 2-3 minutes Only (or ¼-⅓ of the time the cooking instructions on your box show) and then drain the pasta. Pour the drained pasta into the skillet with the chicken along with the remaining chicken broth, parsley and chives and mix to combine.
Heat the butter in a pot over medium heat. Once the butter is sizzling, add the flour. Whisk the flour until it is thickened and bubbling, then add the broth and milk and whisk together. Whisk on medium heat until the sauce starts to bubble. Continue whisking and the sauce will begin to thicken. Add the vinegar, salt, pepper, garlic, and onion powder. Once it’s thick enough that it coats a spoon well, turn the heat off and whisk in half of the shredded cheese. Whisk until the cheese is fully melted and you have a nice cheese sauce. Season to taste with additional salt and pepper as needed.
Preheat your oven to 350 or 375 degrees. Lightly grease a 9x13 baking dish. Pour in half of the chicken and pasta mixture and ladle on half of the sauce all over it, making sure to get the sauce into the edges of the dish. Sprinkle on half of the remaining cheese. Repeat with the remaining chicken pasta, sauce and cheese. Sprinkle the top with black pepper and chopped chives.
Bake for 30-35 minutes, or until the cheese is melted and everything is bubbly. Remove from the oven and allow it to cool and set for 5 minutes or so before topping with more chopped chives and serving.