Monk's side scored four goals before the break as they romped to a 4-1 victory which lifted them to within a point of the play-off places in the Sky Bet Championship table.
Dominic Iorfa, Adam Reach and Steven Fletcher all found the net as Wednesday terrorised the Middlesbrough defence with a succession of crosses into the box, with Adam Clayton's early own goal compounding the home side's misery.
It was comfortably the best 45-minute performance of Monk's brief reign as Wednesday manager and will act as the template for what he wants his side to produce as the season progresses.
Monk said: "It's very pleasing. You're working with players every day on the training ground, but it's one thing doing it on the training ground, you need to then see if they can take it on to the pitch.
"I said it to the players at the end, with that first-half performance they've set a standard in terms of the quality they can produce and how devastating they can be. That's what we have to fight for.
"I thought the first half was exactly what we want to do in terms of delivering certain crosses into the box, showing good movement, and having a real clinical edge.
"That was what we spoke about after the [Carabao Cup] game against Everton in the week – we had our chances in that game but weren't clinical enough. Here, we were ruthless with it, and that's what you have to be."
Monk was dismissed as Middlesbrough manager in December 2017, just hours after he had overseen a win over Wednesday, but he insists he has drawn a line under that chapter of his career.
He said: "That's closed. All I care about is these players and this club and to give that fan-base, fantastic travel, something to shout about.
"My job isn't about me, it's about who you're working with and who you represent and giving them everything you've got."
Boro boss Jonathan Woodgate pulled no punches as he criticised the basic defensive errors that contributed to his side conceding four goals in the opening 34 minutes.
The Teessiders were unable to deal with the physical threat posed by Fletcher and Atdhe Nuhui, and were repeatedly undone by Barry Bannan's set-pieces into the box.
Woodgate said: "It was sloppy, I'm not going to sit up here and say it was good, it was terrible, it wasn't good enough.
"I played a few games at centre-half as you know and you pride yourself by winning aerial battles, no matter who you are up against.
"I played against a lot of different players who are big units but you find a way to beat them in the air, getting yourself in the right position, it's about determination, who wants it more.
"We didn't want it enough in that first half."