1. Preheat oven to 350 degrees.

2. Line a baking sheet with parchment paper; set aside. Halve peppers lengthwise; trim and discard ribs and seeds. Brush peppers with olive oil and place cut side down on prepared baking sheet. Bake until softened and skin has loosened from the flesh, 15 to 20 minutes.

3. Transfer to a bowl and cover with plastic wrap; let steam to loosen skin. When peppers are cool enough to handle, peel off skin and discard any remaining seeds or ribs. Finely chop peppers and transfer to a medium bowl.

4. Add 2 tablespoons olive oil to peppers along with chives and vinegar; season with salt and pepper and toss to combine.