Preheat the oven to 450°F (230°C).
Wash and dry the bell peppers, then cut them in half lengthwise and remove the seeds and stems.
Toss the pepper halves with olive oil, salt, and black pepper until well coated.
Place the peppers, cut side down, on a baking sheet lined with parchment paper.
Roast in the preheated oven for about 25-30 minutes, or until the skin is charred and blistered.
Remove the peppers from the oven and cover them with foil or place them in a bowl covered with a lid to steam for 10 minutes and loosen the skin.
Peel off the charred skin and discard if desired, then drizzle with balsamic vinegar before serving.