Healthy Treats to Use as Training Rewards

So Sammy and I are working on his flight recall and target training, and I am trying to find a treat that is large enough I can easily hold it between two fingers (so no teeeensy tiny seeds) but small enough to eat with one bite. I've been using the pellets he eats for dinner (which are not uber motivating other than right after we wake up) and the small sunflower seeds that come in mixed seeds for cockatiels, but I am looking for a healthier alternative that he will find motivating. I tried those Zupreem fruit blend pellets since they are (from MY personal taste testing--yes, I ate some of the pellets) yummier than the dye free, healthier stuff he is on, but he will not even crack the things! He just drops them to the ground ($8 down the drain with those! If ya live in DFW and want a baggie of Zupreem fruit blend, let me know). I have to BEG him to eat any veggies and fruits at all, so those are not big motivators, and while he likes bread and pizza crust a lot I am looking for stuff that is healthier. I have added several items to try in my cart at MySafeBirdStore (including chopped mixed nuts, gourmet chick peas, and oven fresh bites) but I was hoping some of you guys might have suggestions. I find millet too messy for the training I am trying to do. Are there any particular seeds or nuts that are tasty but less fattening than sunflower seeds that I should look for? Open to suggestions!

Almond slivers and pine nuts are a HUUUGE hit in >this< house.

Popcorn

We use Cheerios. They aren't the best for them since they have soy but Espresso will do almost anything for a Cheerio

Let me know what you come up with he sounds very similar to my baby GCC. I can't find anything for him.. Almonds didn't work, can't get him to touch fruit...

Safflower seeds. All my birds go nuts over them, and they're so tiny that you don't have to worry about giving too much.

If Sammy likes certain fruits, you could also try cutting his favorites up into tiny, smaller than bite-sized chunks. Yes, it'll be slightly messier, but may be worth it if he responds favorably to them.

Some good suggestions here. Just wanted to let you know (depending on your bird) that rewards don't need to be food if theres something else your bird enjoys that motivates him. Mine likes kisses and praise just as much as a food treat Make that kiss noise at him and ask him to do something and after he does, he comes looking for his kiss and "good bird" praise.

Food rewards only work if your bird loves the food you're giving them. You have to know your bird to know what he (or she) likes.