Place a large cast-iron skillet over medium heat. Add the chopped bacon and cook until crisp and browned, about 5 to 7 minutes. Transfer the bacon to a plate with a slotted spoon, leaving about 1 tablespoon of the drippings in the skillet.

Season the chicken with 1/2 teaspoon salt, 1/4 teaspoon black pepper, and the garlic powder. Increase the heat to medium-high and add the chicken to the skillet in a single layer. Cook for 5 to 6 minutes, stirring occasionally, until lightly browned and cooked through. Transfer to a plate.

If the skillet looks dry, add the olive oil. Add the Brussels sprouts and butternut squash. Cook for 6 to 8 minutes, stirring occasionally, until they begin to soften and brown around the edges.

Add the diced onion and cook for 3 minutes, until softened. Stir in the minced garlic, smoked paprika, dried thyme, remaining 1/2 teaspoon salt, and remaining 1/4 teaspoon black pepper. Cook for 30 seconds, until fragrant.

Return the cooked chicken and bacon to the skillet. Toss everything together and cook for 2 to 3 minutes, until the vegetables are tender and the flavors are blended.

Drizzle in the apple cider vinegar and stir well, scraping up any browned bits from the bottom of the pan. Taste and adjust seasoning if needed.

Sprinkle with chopped parsley and serve warm.