Begin by bringing a large pot of salted water to a rolling boil. Add the Brussels sprouts and let them cook for 4-5 minutes until they are just tender but still bright green. Drain them and immediately transfer to an ice bath to halt the cooking process.

In a large skillet, over medium heat, add chopped bacon and cook for about 7-8 minutes until crispy and golden brown. Remove bacon with a slotted spoon, letting excess fat drain on paper towels while leaving rendered fat in the skillet.

Increase the heat to medium-high and add blanched Brussels sprouts and chopped pecans to the bacon fat in the skillet. Sauté for about 4-5 minutes until crispy and caramelized, stirring frequently.

Sprinkle ground mustard over the Brussels sprouts and pecans, stirring for 1 minute to coat the vegetables with mustard.

Pour in the bourbon (or apple cider vinegar) and scrape any browned bits from the bottom of the skillet. This should take about 2-3 minutes, allowing the liquid to reduce.

Return the crispy bacon to the skillet, then drizzle in the maple syrup, tossing everything together until well-combined. Cook for 1 additional minute to thicken slightly.

Taste and adjust seasoning with ground pepper or additional salt if needed. Serve immediately while hot.