Preparation

• In a Dutch oven or a heavy stockpot, heat the oil over medium-high heat. Add the peppers, potato, onion, salt, and red pepper flakes. Cook, stirring, for a minute or two. Reduce the heat to low, cover, and simmer, stirring occasionally, until the vegetables are tender, about 1 hour. Transfer to a blender or food processor and purée in batches, or purée thoroughly with a hand blender. Force the purée through a coarse sieve or a food mill. Transfer to a saucepan and stir in the chicken stock, adding a bit more if you like a thinner soup. Adjust the seasonings. Serve warm or cold, garnished with a dab of sour cream or crème fraîche and a sprig of dill.