I added 1 tsp. of ground mustard and 1 sauteed onion that's chopped finely to this recipe. I always double these recipes and make a large casserole of it. After serving for dinner, we love having it for lunch the following day too. Think it's even better b/c the flavors have had more time to marinate together.
So many ways to add more flavor to this dish as well, with hot pepper, broccoli florets, chopped red and green bell peppers, etc. Let your creative juices flow!