My baby won't chew anything but Puffs?

11 months old, still nursing, still getting organic jarred baby foods, but the only thing he'll pick up and chew are the Gerber puffs, and he LOVES them! I've tried soft fruits and steamed veggies cut in very small pieces, but he sort of gnaws, looking miserable, then either spits them out or gags them down. It doesn't look very pleasant. Any ideas?