Chop 1 onion, sauté until golden in butter or olive oil. If desired, chop some garlic and one or more chilies or banana peppers, add to pan after onion is golden and continue to sauté. Also if desired, slice about a half cup fresh mushrooms, add to pan after onion is golden and continue to sauté until nicely browned.
For each person, grate 1 to 2 oz sharp cheddar cheese. Other cheeses may be used as desired, and more is better than less. Have on hand about an ounce of cream cheese per person, cut into small chunks.
Grease well with butter a casserole of an appropriate size. Start layering in casserole--a thin layer of pasta, layer of sautéed vegetables, layer of grated cheese and a few chunks of cream cheese, sprinkle with black pepper, cayenne, and nutmeg (very small amount of nutmeg). Keep layering, holding back some cheese and ending with a layer of pasta. Put the last of the cheese, including some cream cheese, on top of the last pasta layer. If desired, top with sliced tomato and/or grated Romano along with the other cheeses. Dot with butter.
Put uncovered casserole in oven. Bake about 40 minutes, until top layer of cheese is melted and top cream cheese chunks are golden brown and butter in casserole is bubbly.
Serve piping hot.