Preheat the oven to 400 degrees F.
Wash brussel sprouts, then cut in half.
Heat a skillet over medium high heat. Add the pancetta and cook for 7 minutes. Once cooked, add in the balsamic vinegar, brussel sprouts, and garlic. Season with a pinch of salt and pepper and saute for 5 minutes.
Remove from heat and add to a large mixing bowl. Add chopped walnuts, dijon mustard, olive oil, salt, and pepper and toss to coat. Pour into a casserole dish and place into the oven on the center rack. Cook for 15 minutes.
Top with pomegranate seeds and feta.
