My LO was the same. Just keep offering. Different sizes and shapes, different colours. Blueberries were the breakthrough for us, he thought they were sweeties, and went from there to eating anything cut to blueberry size. And only put a couple of little bits on the highchair tray, that way there won't be so much clean up and it will be less frustrating.
Oh yes, another thing my LO liked was to have 3 tiny containers (maybe like muffin tin liners) with tiny bits in - a few tiny cubes of cheese, a few blueberries, a few peas.