Prepare spaghetti squash by either of the following methods: *Poke squash in several places and microwave 15 min. on high power, turning over after 8 minutes. Cook longer if necessary, until squash is tender but still slightly firm. Cut in half, cool slightly before handling. Remove seeds (may reserve for roasting a tasty snack). Then spaghetti, using a fork to scrape pulp from inside of shells. Place pulp in colander to drain.** OR *Preheat oven to 350 F. Cut squash in half. Scrape out seeds. Bake, cut sides down, on lightly greased, rimmed baking sheet until tender but still a bit firm, 45 min-1 hour. Turn halves over and let cool slightly before handling. Then spaghetti, using a fork to scrape pulp from inside of shells. Place in colander to drain.** While squash bakes saute onions and garlic in oil, until soft and translucent. Preheat oven, or increase oven temperature, to 400F. Lightly grease 10x15-inch baking dish. In large mixing bowl, combine bread crumbs, red pepper, salt and pepper. Stir in onions and garlic. Add the parsley, mozzarella and cheddar cheeses and stir to combine. Fold in cooked, drained, squash and mix well. Pour into prepared pan. Bake for 30-40 minutes, until bubbling and browned on top. ** If shells remain firm and intact you may fill the shells with prepared casserole mixture and bake right in the shells. Place filled shells on rimmed baking sheet and bake as above.