The phrase "once immediately" is correct and usable in written English.
You can use it to emphasize the immediacy of an action. For example, "After we discussed the plan, I knew I had to act once immediately."
A button press response consists of pressing the spacebar on the computer keyboard ONCE AND ONLY ONCE immediately after the button appears.
Wearing sunglasses and headphones, he appears at once immediately present, filling half the frame, and distant, absorbed in filming, like an auteur in control of the picture.
Because they are at once immediately recognizable but at a safe distance outside one's self, classic television characters like Archie Bunker can provide an insightful lens on the vagaries of modern life.
The image in our mind's eye pictures a painting that pictures a moment in historical time — note the map of Europe on the wall — that may or may not have actually happened but that in any case appears at once immediately real and distantly fictive.
This is the newest museum on the National Mall in Washington, DC, and its design, by the Ghanaian-British architect David Adjaye, is so successful, at once immediately iconic and bold but also somehow blending into the low-slung surrounding architecture, that it has become the most talked-about building in the United States.
For day one, ISA measures were taken at 5 min intervals, and the SWAT measure was taken once during the run at approximately 30 min, and once immediately after the run.
Once done, immediately drop the eggs in a bowl of iced water.
"After some incessant nagging, I did it at once and immediately felt creepy and sinister," the teacher wrote.
Caesar, once consul, immediately forced through a land bill and, shortly after, another appropriating public lands in Campania.
2. Once reduced, immediately add salt and blend until the salt has completely absorbed the wine and changed color.
Contact smears were taken once daily, immediately before application of the oestrogen cream.
