Preheat the oven to 400 degrees F. Cut the Brussels sprouts in half lengthwise, from top to bottom. Toss the sprouts with olive oil, 1/2 teaspoon salt and the red pepper flakes on a baking sheet. Put in the oven and roast until tender, about 20 minutes. Toast the pine nuts on a separate baking sheet in the oven for the last 5 minutes of roasting the sprouts.
While the sprouts are roasting, put the bacon in a small saute pan with a splash of olive oil and bring the pan to medium heat. Cook the bacon until crispy, 7 to 8 minutes. Remove from the pan.
Toss the roasted Brussels sprouts with the crispy bacon and toasted pine nuts. Using a peeler, shave a few slices of parmigiano on top.