Situation You say borei pri ha'eitz and eat a few olives, but less than 1.3 fl. oz. Then, you say borei pri ha'adama and eat lettuce mixed with enough olives to constitute the minimum volume when combined with the first olives.  You eat them all within four minutes. It is time to say the after-blessing.
What To Do You may not combine all the olives in order to say the after-blessing of al ha'eitz unless the olives remain distinct from the lettuce and you continue to eat them separately.  Say borei nefashot after finishing eating as long as the total food eaten was at least 1.3 fl. oz.