How old is your LO?
A full jar is a lot for a first meal. I just started DS2 on solids and though he would have eaten more I only gave him a couple of tablespoons of baby food for the first few days to be able to see if there is a reaction and then I am going to slowly increase it. He gobbles it up so happily and I feel bad only giving him a little bit, as everything else has been such a battle with him (reflux, food intolerances etc), but I know that slow and steady is the best way to do it!!