high-hanging fruit

noun2

1. •
   Fruit that, because of its height from the ground, is more difficult to harvest.
2. •
   (figurative) Anything that is difficult to achieve, and which is postponed while simpler alternatives are still available.

   • The smaller research-based centers will tackle the much more difficult to express, high-hanging fruit, in particular, represented by membrane and posttransationally modified proteins. — 2007