Many years ago we visited an aviary that had a lot of different species of birds. The smaller species were in one aviary & larger species in a 2nd aviary. The smaller aviary had a bird that had lost it's bottom beak in a fight. I watched it eating seeds. I was cracking them with it's tongue.
There is no telling, for now, if your bird will ever be able to crack seeds again. For now I would suggest you mince or puree veggies & fruits. I have a Ninja Express mini food chopper. You can chop or mince veggies, fruits, nuts, pellets & other foods & even puree them. The unit is electric & works via a manual press button, so you can control how small you chop or mince by pressing the button. The Ninja mini chopper is a 2 cup unit that is easy to use, comes with a lid to store left over in frig, is easy to clean. Caution when handling the blade as it's very sharp. I've had mine for many years. Got mine at Walmart, but they sell them on line & at many stores. The price varies depending on where you buy. I got mine for around $20.00 several plus years ago. It's a great little chopper. If you have to mince/chop foods for a long time for your bird I'd suggest this chopper. FYI: I am not affiliated with this company in any way. Just love this food chopper.