Follow instructions for Fresh-Herb Deviled Eggs through step 2.
Place 6 bell peppers, 1 at a time, directly over the flame of a gas-stove burner on high heat. Roast peppers, turning with tongs, until blackened all over. (Alternatively, broil peppers on a baking sheet, turning, until skin has charred.) Transfer to a large bowl, and cover immediately with plastic wrap. Set aside to steam 15 minutes. Peel peppers; discard skins. Remove stems, seeds, and ribs; cut each pepper into large pieces.
Transfer peppers to a food processor; process until smooth, about 2 minutes. Spread puree onto a baking sheet lined with 3 layers of paper towels; top with more paper towels, and press gently to soak up excess liquid, changing paper towels as needed until drained. Add puree and the creme fraiche to yolks; stir to combine. Season with salt and pepper.
Cut remaining 1/2 bell pepper into thin matchsticks; curl each around your little finger, press gently, then uncurl. Proceed with instructions for step 4 of the Fresh-Herb Deviled Eggs, garnishing instead with red-pepper curls.