Step 1: Sear the Seasoned Chicken
Pat the chicken cubes dry with paper towels. Season generously with smoked paprika, garlic powder, onion powder, salt, and pepper. Heat 1 tablespoon of olive oil in a large, deep skillet (12-inch or larger) or braiser over medium-high heat. Add the chicken in a single layer and sear for 3-4 minutes per side, until golden brown on the outside but not fully cooked through. Remove the chicken to a clean plate.

Step 2: Sauté the Aromatics
In the same skillet, add another tablespoon of oil or butter. Add the diced onion and cook for 4-5 minutes until softened and translucent. Add the minced garlic and cook for 1 more minute until fragrant.

Step 3: Build the Honey BBQ Cooking Liquid
Pour in the chicken broth to deglaze the pan, scraping up all the flavorful browned bits (fond) from the bottom with a wooden spoon. This is where deep flavor lives. Whisk in the BBQ sauce, honey, tomato paste, apple cider vinegar, Worcestershire sauce, and dry mustard (if using) until smooth.

Step 4: Simmer the Pasta in the Flavorful Broth
Bring the sauce mixture to a boil. Stir in the dry elbow macaroni. Reduce the heat to a steady simmer, cover the skillet with a lid, and cook for 10-12 minutes, stirring occasionally, until the pasta is al dente and has absorbed most of the liquid.

Step 5: Finish the Sauce and Add Chicken Back
Reduce the heat to low. Stir in the room-temperature milk or half-and-half. Return the seared chicken (and any accumulated juices) to the skillet. Stir everything together and let it simmer, uncovered, for 3-4 minutes, until the chicken is cooked through and the sauce has thickened slightly to coat the pasta.

Step 6: Melt the Cheese Into Creamy Perfection
Remove the skillet from the heat. Stir in 1 ½ cups of the shredded cheddar cheese and all of the Monterey Jack cheese until fully melted, smooth, and creamy. The residual heat will melt the cheese perfectly without scorching.

Step 7: Garnish and Serve
Sprinkle the remaining ½ cup of cheddar cheese over the top. Cover the skillet for 2-3 minutes to let the residual heat melt the topping cheese. Garnish lavishly with sliced green onions and fresh parsley. Serve immediately, directly from the skillet.