How can i fix this problem with home made soup?

i used to work at a pizza place and i got their recipe for pasta fagioli. you have to process the carrots celery and onion saute them then add liquid and the beans but that was over 6 yrs ago and i cant find the recipe and they closed since then. so i made it from memory and the carrots and celery are not melting into the soup its just minced floating in it. did i miss a step? what did i do wrong?