The phrase "after we ordered" is correct and usable in written English.
It can be used to indicate a time or event that occurs following the act of placing an order, often in contexts related to dining or purchasing.
Example: "After we ordered, the waiter brought us our drinks while we waited for our meals."
Alternatives: "once we placed our order" or "following our order".
Our breakfast was delivered just 25 minutes after we ordered it.
After we ordered, Simpson sat against the wall and looked around the crowded dining room.
After we ordered, Baber explained why his version of an armed robot was destined to succeed.
After we ordered, she asked, "Do you want to see my pic with Justin Trudeau?" She scrolled through her phone.
We sat down by the window, and soon after we ordered Marclay's face was tinted by a rainbow splash of neon.
After we ordered rabbit pies, I retrieved from my backpack some T.I.B.C. loan applications that had been leaked to Ernst & Young.
"Yes!" "To equal pay!" Someone whispered, "Should we wait until after we order our food to say anything?" The members of the group were mostly women, and mostly lawyers, as was their guest of honor, Karen DeCrow, who had proposed the toast.
Jocelyn picks the same, and, after we order, Lou hands her something under the table.
Our appetizers arrive perhaps five minutes after we order them, an example of an assembly-line quality that pervades the evening.
Shortly after we order, our server approaches with a gray tub containing a wriggling, upside-down Dungeness crab, freshly plucked from the restaurant's live seafood tanks.
After we order most of his menu, owner Armando de la Torre takes us to the grocery shop next door where, incongruously, he gets his corn cooked, skinned, hoppered and ground, and then hand-makes it into tortillas or adds lard to make masa for tamales (stuffed steamed breads) or conchas (sweet pastries).
