Melt the butter in a large skillet. Add the onion and sauté until transparent. Add the cabbage and sauté for 5 minutes or until tender but still crisp. Stir in the caraway seeds, salt and pepper. Meanwhile cook the noodles in salted water as directed on the package. Do not overcook. Drain well. Stir the noodles into the cabbage and add the sour cream. Cook for 5 minutes longer, stirring frequently. Serves 4 -6