Adapted from Jamie at Home
- 10 medium-sized hot red peppers, such as red jalapeños or fresnos
- 8 medium red bell peppers
- 1 tablespoon olive oil
- 2 medium red onions, sliced
- 1 tablespoon finely chopped fresh rosemary
- 2 bay leaves
- 1 2-inch piece of cinnamon stick
- Kosher salt
- Freshly ground black pepper
- 1/2 cup brown sugar
- 2/3 cup balsamic vinegar
Roast peppers over gas stove, grill, or broiler until skins are completely charred. Place in a bowl, cover with plastic wrap, and let sit until cool enough to handle, about 15 to 20 minutes. Remove charred outer skins, cut in half, and remove seeds and cores. Finely chop peppers.
Heat oil until shimmering in a medium saucepan over medium heat. Add in onions, rosemary, bay leaves, and cinnamon, and season lightly with salt and pepper. Cook, stirring occasionally, until onions have completely softened and darkened, about 20 minutes.
Stir in chopped peppers, sugar, and vinegar. Continue to cook, stirring occasionally, until liquid is reduced and mixture is thick and syrupy, about 30 minutes. Remove cinnamon and bay leaf. Season with salt and pepper to taste. Transfer to a glass jar and store in refrigerator for up to a month.