I do agree it *could*
make a dog fussy but i would be "eat it or go hungry" if that happened.
Nature menu at Pets at Home do a good range of frozen nuggets made of various things.I use the fruit/veg and rosemary ones.
I also occasionally use..
meat juices
grated carrot/cheese
tinned sardines
1 or 2 defrosted whitebait
Everything in moderation as the kibble should be tasty enough on it's own soaked in a little warm water and also dogs have no where near as many taste buds as we do.