Char whole chile directly over gas flame or in broiler until blackened on all sides. Transfer to paper bag; seal. Let stand 15 minutes. Peel, seed, and coarsely chop chile. Transfer to processor; puree until smooth. Set aside.
Heat oil in heavy large saucepan over medium-high heat. Add 1/4 cup chopped chile, bell pepper, onion and garlic. Saute until soft, about 4 minutes. Add corn; stir 1 minutes.
Add cream and chile puree' bring to boil. Add cooked macaroni and grated cheese; stir until cheese melts and mixture is heated through. Season to taste with salt and pepper.