Kyle Walker-Peters, Jaden Brown and Will Miller were also on target as we controlled the behind-closed-doors friendly at Hotspur Way.
Walker-Peters instigated the opening goal on 11 minutes. Always an outlet on the right, he escaped two challenges before picking a reverse pass to Kazaiah Sterling. His cross was touched back by Nkoudou for Walker-Peters to measure a left-foot finish into the bottom corner.
Onomah was denied by Charlie Grainger in the Orient goal before O's right-back Tristan Abrahams forced Michel Vorm into the action, the goalkeeper did well to hold onto a 25-yarder diving to his right.
Nkoudou doubled our lead on 36 minutes, shifting left and right before arrowing his shot across Grainger into the far corner from the left angle. It was a purple patch for the Frenchman, who soon set-up Onomah, fired just wide himself and then tested Grainger again from distance.
Below: Jaden Brown congratulated after making it 3-0
Both teams made changes at half-time and Orient were first to register an effort in the second half as Aaron Pollock broke from deep, played a one-two and drilled straight at Vorm.
Joe Pritchard was inches away from 20 yards and as we stepped it up again, Anthony Georgiou took Timothy Eyoma’s pass in his stride in a dart to the left byine and crossed for Shayon Harrison, whose backheel was cleared off the line.
We made it 3-0 on 71 minutes with a carbon-copy move, Georgiou sped to the byline and his cross found Jaden Brown who got the ball out of his feet before rifling into the roof of the net from 14 yards.
It was soon 4-0. This time Will Miller broke from deep and rolled in a pass to Harrison, the striker held off his defender to touch the ball back into Miller’s path, Miller took it in his stride and clipped over advancing O's keeper Sam Sargent.
A fifth goal somehow eluded us. Sargent produced the save of the game to tip away Nkoudou’s 25-yarder and then grabbed Harrison’s drive before spilling Nkoudou’s shot dangerously close to the goalline. Dylan Duncan’s volley whistled narrowly wide and the final action saw Nkoudou burst onto Luke Amos’ pass only to plant his one-on-one chance just over.