Mix the salt and cabbage together and let stand 30 minutes. Squeeze out as much liquid as possible. Heat the butter in a deep skillet, add the onions, cabbage, sugar and pepper. Cook over low heat, stirring frequently, until cabbage is browned, about 25/30 minutes. Add the noodles and toss to blend thoroughly. Note: To reduce fat, you can use just 1 tablespoon butter and saute the cabbage for a few minutes, then finish with a little chicken stock, stirring frequently.