Preparation Char bell pepper over gas flame or in broiler until blackened on all sides. Enclose in paper bag; let stand 10 minutes. Peel, seed and coarsely chop bell pepper. Transfer to processor. Add oil, oregano and garlic; puree until smooth. Season coulis with salt and pepper. Preheat oven to 500°F. Line large baking sheet with foil. Arrange clams on sheet. Bake until clams open, about 6 minutes (discard any that do not open). Cool slightly. Remove top shells; discard, leaving clams in half shells on sheet. Preheat broiler. Top each clam with 1 teaspoon coulis, then 1 pancetta piece. Broil clams until coulis bubbles and pancetta browns, about 3 minutes. Transfer to platter. Garnish with lemon; serve.