Agree with the previous reviewer that thought adding onion and possibly carrots would be good. I think you could mix in/ saute whatever veggies you have on hand (celery, sweet peppers, etc.)! I made mine ahead of time, and then put it in a dish to bake later. I sprinkled some cheddar cheese on top- I think that's always a nice add-on. My only other thought is that this casserole didn't really hold together- I suppose you could always stir in some cream-of-something soup to make it creamy and not so crumbly. My kid liked it all right- started eating around the peas about halfway through dinner, though!
We thought this was really good but I made one change. I did add 1/2 cup of sautéed onion at the same time I added the peas. I believe it made a big difference. Will make this again. Also thinking some carrot might be good in this dish.