Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Trim the ends of the Brussels sprouts and halve them vertically to ensure even roasting.
In a large skillet over medium heat, cook the diced pancetta until it becomes golden and crispy.
Remove the pancetta with a slotted spoon, leaving the rendered fat in the pan, and set aside on a paper towel.
Season the chicken breast with half of the sea salt and black pepper, then sear in the skillet for 5-6 minutes per side until fully cooked.
Toss the Brussels sprouts with olive oil, minced garlic, and the remaining salt and pepper on the prepared baking sheet.
Roast the sprouts for 20-25 minutes until tender and charred on the edges.
While roasting, whisk the balsamic vinegar and honey in a small saucepan over low heat until it thickens into a glossy glaze.
Slice the cooked chicken and combine it with the roasted sprouts and crispy pancetta in a large bowl.
Drizzle the velvety balsamic glaze over the mixture and toss gently before serving.