01 - Bring a large pot of salted water to a boil. Add Brussels sprouts and blanch for 3 to 4 minutes until just tender. Drain thoroughly and set aside.
02 - Heat a large skillet over medium heat. Cook diced bacon, stirring occasionally, for 5 to 7 minutes until golden and crispy. Remove bacon with a slotted spoon, placing on paper towels to drain. Reserve 2 tablespoons rendered bacon fat in the skillet.
03 - Add sliced red onion to the reserved bacon fat in the skillet and sauté for 2 minutes until slightly softened.
04 - Add blanched Brussels sprouts to the skillet and cook, stirring occasionally, for 3 to 4 minutes until lightly caramelized.
05 - In a mixing bowl, whisk together olive oil, Dijon mustard, red wine vinegar, honey, salt, and pepper until emulsified.
06 - Return cooked bacon to the skillet, pour dressing over, and toss all ingredients together over low heat until evenly coated and warmed through.
07 - Transfer salad to a serving platter. Garnish with chopped parsley and toasted walnuts if desired. Serve immediately.