Preheat oven to 400 degrees. Spread pine nuts on a baking sheet and bake until fragrant, about 5 minutes. Remove and let cool.
Place peppers directly over the trivet of a gas-stove burner over high heat, or on a grill. Just as each section turns puffy and black, turn pepper with tongs to prevent overcooking. (If you don't have a gas stove, place peppers on a baking pan, and broil in the oven, turning as each side becomes charred.) Transfer peppers to a large bowl, and cover immediately with plastic wrap. Let peppers sweat until they are cool enough to handle, about 15 minutes; then transfer to a work surface. Peel off the blackened skin and discard.
Coarsely chop peppers and transfer to a food processor. Add pine nuts. With machine running, add olive oil in a steady stream. Continue processing, scraping down the sides as needed until pureed. Season with salt and pepper.