1. Preheat the oven to 500 degrees Fahrenheit. Line a roasting pan with enough foil to later fold over the top. Place the peppers in the pan and the pan in the oven. Roast, turning the peppers about every 10 minutes, until the peppers collapse, about 40 minutes.
2. Fold the foil over the peppers and allow them to cool. Work over a bowl and remove the core, skin, and seeds from each of the peppers, reserving some of the liquid.
3. Place the pepper pulp in the container of a food processor with about 2 tablespoons of the reserved liquid. Add a large pinch of salt and turn on the machine; drizzle the oil in through the feed tube. Stop the machine, then taste and add more salt and/or olive oil if necessary. Store, well covered, in the refrigerator (for several days) or the freezer (up to a month).
10 Simple Uses for Red Pepper Purée
Mark Bittman is the author of the New York Times column The Minimalist Cook.
"Vegetables are perishable, so we don't have any indication of what they looked like 500 years ago," says James Nienhuis, a professor in the Department of Horticulture at the University of Wisconsin.