Gokyo Ri (5357m/ 17575) is  great training peak above the town of Gokyo. It has one of the best views in the Khumbu, with views of Mount Everest and the blue waters of Gokyo Lake. It is a steep climb at altitude, so don't let the numbers deceive you! The segment begins at the base of the climb, where the trail sign is (so cross the stream first) and ends when you touch the prayer flags up top. 

Alternatively, the Mera Mera-thon!

(Editor's note: Adding two FKTs here as variations. The "Mera-thon" from Lukla as well as the more traditional summit from Khare village).