so they like creamy carb things?
How about shepherd's pie
enchilada casserole (you don't have to make it spicy- it can just be creamy)
baked fries
Cheesy sauces are great for blending carrots or other orange veggies into
Herbs are really good for you, too. Oregano has lots of antioxidants in it (and they don't need much to get a benefit) as well as other herbs and spices. So if they won't do veggies, do all the herbs they will eat!