Heat the broiler and put the peppers close to the heat until they blacken and blister. Turn them over until the outside is at least 75 percent black. Let them cool enough to handle, then peel off the skin (it will come off easily). Cut the top one-quarter of the pepper off, and lift out the stem, seeds, and membrane. Try to keep from tearing the bottom part of the pepper while doing all this. Rinse the pepper bottoms in cold water, then set aside.
After removing the seeds and stems, chop the remaining top part of the bell pepper. Chop half of the crawfish into about the size of peas.
Heat the olive oil in a large skillet over medium heat. Add the onion and celery, and cook until soft. Add the chopped bell pepper, crawfish, and 1/4 cup of water (or shrimp or crawfish stock, if you have it). Bring to a boil and stir for a couple of minutes.
Remove the pan from the heat and stir in the rest of the stuffing ingredients.
Carefully fill the peppers with the stuffing. Try not to tear the peppers. Place the stuffed peppers on an oiled baking pan and into the preheated oven for 15 minutes.
While they're in there, make the sauce. Heat the olive oil in a skillet and saute the green onions and fennel or celery until soft. Add the red pepper flakes and wine and cook for about three minutes. Whisk in the cream and bring it to a boil over medium heat until reduced by about half--five or six minutes. Add salt to taste.
Add the sun-dried tomatoes, the prosciutto, and the remaining chopped crawfish. Heat through. Add the cooked, drained pasta to the pan and toss with the sauce.
Serve the pasta alongside the peppers. Garnish with fresh chopped flat-leaf parsley.