I could answer better if you had given the boss name but here is the first boss of the game i found that seems like Jak and Daxter one.
"An easy one. Get in a corner and wait for the insect to become vulnerable. Spin
kick it. The plant will show its leaves. Jump on them and spin kick the flower.
Get back in the corner and kill the first insect. Get in the other corner and
kill the next insect. Get on the leaves. Spin kick the flower once again and
get back in a corner. Kill the insect, get in the other corner, kill the
insect, get in the other corner, kill the insect, get on the leaves, spin kick
the flower, get the power cell, get the precursor orbs by jumping on the dead
flower, leave with the jumping platform."