How to Make It
Roast the red peppers directly over a gas flame or under the broiler, turning occasionally, until the peppers are blackened all over. Transfer the peppers to a bowl and let cool completely. Peel the peppers and discard the skins, seeds and cores. Coarsely chop the peppers.
In a food processor, combine the peppers with the olive oil, shallot and vinegar and puree until very smooth. Season the coulis with salt and white pepper.