Cut squash in half lengthwise; scoop out seeds. Place with cut side down in a baking dish; add water. Cover and bake at 375° for 20-30 minutes or until it is easily pierced with a fork. When cool enough to handle, scoop out squash, separating the strands with a fork. In a skillet, cook beef, onion, red pepper and garlic until meat is browned and the vegetables are tender. Drain; add tomatoes, oregano, salt, pepper and squash. Cook and stir for 1-2 minutes or until liquid is absorbed. Transfer to an ungreased 1 1/2-quart baking dish. Bake, uncovered, at 350° for 25 minutes. Sprinkle with the cheese and parsley; let stand a few minutes.