Well, my birds don't like chop either! And I don't blame them one single bit because I've never seen chop that looks appetizing to me
Now, quakers are EXCELLENT eaters and I do mean super excellent. My Keku eats HUGE amounts of leafy greens and anybody who has had parrots for a while will tell you that leafy greens are BY FAR the most difficult thing to get them to eat! Try gloop. I have transitioned literally and without exaggeration (I used to run a rescue) hundreds of parrots to gloop and they all love it. Plus, it's super nutritious, easy to digest and very versatile when it comes to flavors.
There are several recipes of gloop in the diet section but, basically, it's cooked grains mixed with chopped veggies. My gloop has kamut, spelt, hulled barley, oat groats, red and black rice and lentils. Once this is all cooked and cooled, I mix unthawed frozen veggies (unthawed because you want to wait until the last minute to thaw them as frozen veggies are the most nutritious of them all -more than fresh and much more than cooked) into it, bag it into daily portions and frozen so I can take out one bag at a time. I use corn, peas, carrots, butternut squash and chopped broccoli but i also add cooked sweet potatoes (baked, boiled or nuked in the skin and then peeeled and chunked.
The thing about chop is that it has no protein whatsoever so birds are not attracted to it while gloop, having cooked grains which resemble seeds (you need to cook them al dente) in their shape and have low protein so birds like them. And, as the veggies are all either of a small size (peas and corn) and the others are in small pieces (diced carrots and butternut squash and chopped broccoli), they end up eating a good meal all in one helping.
But it also helps if you time it correctly because one very useful trick that we, bird keepers, have is to follow their natural circadian cycle routine so we feed them breakfast (the healthiest food) right after the sky is lit enough for them to see well -and when they are hungriest! But do not free-feed any protein food (pellets, seeds, nutriberries, avicakes, etc) because, if you do, the birds will go for the protein and not touch the healthy stuff.
Let us know how it works out and ask anything that you might have doubts on.