Pierce squash with fork in several places. Place on baking sheet and bake at 350F 45 minutes. Turn and bake 45 minutes longer, or until shell yields to pressure. When cool enough to handle, cut squash in half. Scoop out and discard seeds. Remove spaghetti- like strings inside squash with fork and reserve. Melt butter in skillet. Saute onion and green and red peppers until tender. Add squash strands, oregano, marjoram, basil, garlic, cheese and olives. Season to taste with salt and pepper. Toss until cheese is evenly distributed. Place in 1 1/2-quart casserole and return to oven until cheese is melted, 10 to 15 minutes.
(C) 1992 The Los Angeles Times