Four collections of his JAM related work and short stories are available in freshly produced print-on-demand copies from About Comics, details here.
Here's a sampling of his work. More on them will be added below.
This is from the story "The Tragic Though Amusing History of Clay Face II", SECRET ORIGINS #44 [1989], written by Dan Raspler, inked by Denis Rodier. A loose re-telling of the silver age origin of the Batman villain with four very different versions (probably even more now). Very entertaining version of Batman. Apparently done as a rush job to replace a Mike Mignola drawn story which was either rejected or lost, depending on who you ask.
From THE TRUE NORTH [1988], a benefit comic for comic facing censorship comes this page from a two page story by Mireault, inked by frequent collaborator Joe Matt. Nice experimental playful use of the comics form in a very funny story. He did, however, eventually work for Marvel. Not a lot, and mostly for imprints, not Marvel proper, and mostly colouring. But there it is...
This cover for AMAZING HEROES #131 [1987] features a Grendel illustration by Mireault, inset with a Steve Rude image of another character who shared a publisher with Grendel. Mireault had a long association with Matt Wagner and Grendel, working as an artist, inker or colourist on many of the major stories. He also was cast as a character, "Kirby Hero", in Wagner's Mage series, alongside Joe Matt as "Joe Phat". More Grendel later.
From TROLLORDS #15 [1988], the long-running series created by Scott Beaderstadt and Paul Fricke. Many issues of the series featured other independent comics creators taking a back-up story, this time it was Mireault with writer Mark Shainblum doing "Death and Taxes Take a Holiday", a nice story consistent with the series but very much in Mireault's style. 
Mireault contributed to a few of Jim Ottaviani's comics about science and scientists, including the framing sequences in FALLOUT [2001], a biography of Robert Oppenheimer. Fascinating story, someone should make a movie based on it...
Somehow the censorship problem wasn't solved in 1988, so Mireault was back in THE TRUE NORTH II [1991], this time with "Benefit", a very frantic tale of rock and roll in Montreal written and inked by Rick Trembles. And thus the problem of censorship was solved once and for all... what do you mean you have some bad news for me?
For Michael T. Gilbert's MR. MONSTER PRESENTS (CRACK-A-BOOM!) #3 [1997] Mireault draws a long 12-page ghost story, "Asphalt Tomb", written by Scott Deschaine and layouts by Deschaine and Gilbert. A very chilly story with some interesting visual flourishes.
Probably Mireault's most widely read work was "When Is A Door", the 10-page not-really-origin of the Batman villain Riddler from SECRET ORIGINS SPECIAL #1 [1989], written by Neil Gaiman, inked by Matt Wagner and coloured by Joe Matt. A brilliant little story told with style, using the classic gimmicks from Batman creator Bill Finger stories of giant props to great effect. 
A nice playful image of Mireault's Jam from AMAZING HEROES SWIMSUIT SPECIAL '91 [1991], showing off his skill at portraying the urban landscape of Montreal that featured in the series.
One of Mireault's solo art jobs with writer Matt Wagner on Wagner's signature character Grendel, as reprinted in GRENDEL OMNIBUS #1 [2012] (originally published in 1998). Entertaining story about Hunter Rose, the one true Grendel.
Another science non-fiction collaboration with Jim Ottaviani, this one some vignettes on the life of Richard Feynman in his days on the Manhattan Project published as TWO-FISTED SCIENCE - SAFECRACKER [1997], also included in TWO-FISTED SCIENCE [1997]. This is where I first heard of Feynman, and inspired me to read several of his books, which ended up being very helpful to me at that point in my life. 
Doug Murray wrote this anthology series of tales of winners of the Medal of Honor. For MEDAL OF HONOR #3 [1994] Mireault draws "The Andrews Raid", a daring 1862 operation during the Slaveholders' Rebellion which resulted in the awarding of the very first Medals of Honor by Abraham Lincoln. Very energetic telling of the story (which was also dramatized as film THE GREAT LOCOMOTIVE CHASE [1956]).
MACKENZIE QUEEN was Mireault's first solo book from 1985, running for five issues and telling a really bizarre story of aliens, super-powers and monsters. Hard to describe, but well worth seeking out, with all of the trademark dynamics, experimentation and humanity that would figure into all of Mireault's subsequent work.
Like this classic bit from THE JAM - SUPER COOL COLOR INJECTED TURBO ADVENTURE #1 [1988], which is just packed with weird concepts and manic energy.
Mireault was an early contributor to Stephen Bissette's horror anthology TABOO, featured in the first three issues with stories like "Cable" in TABOO #1 [1988] really setting the stage for what the book was aspiring to.
"Too Many Santas" is a nice little story that appeared in COMICO CHRISTMAS SPECIAL #1 [1988], with various seasonal stories written by Doug Wheeler. Memorable even in a book with a Dave Stevens cover and Al Williamson inking Steve Rude inside.
Dr. Robot was a dialogue-free back-up feature in Michael Allred's MADMAN, collected with a new story in DR. ROBOT SPECIAL #1 [2000]. A delight, with Mireault's skill at expressions, body language and sound effects combining with his distinctive colours to tell some fun stories.
Speaking of Allred's Madman, you can't go wrong by seeking out the two issue MADMAN / THE JAM series from 1998. The two off-beat heroes blend perfectly in the story called "House of Escher", and you can guess what that entails. I believe reprinted in various Madman collections, most recent MADMAN LIBRARY EDITION #2 [2022].
Steve Moncuse was another 1980s indy creator who invited others to play in his sandbox in back-ups, called "Fish Shticks", so FISH POLICE #12 [1988] features a 4-page back-up written by Moncuse and everything elsed by Mireault. A lot of fun.
Back to horror with Stephen Bissette's TABOO #3 [1989] and the story "Poker Face", which is really grisly and not for the faint of heart after this page. But worth it.
And to take us out, CRITTERS #50 [1990] has another Canadian comics mainstay, Ty Templeton, telling an autobiographical story (except, presumably, for the part where the characters are bears. But hey, stranger things are true) about fast food and rules. Templeton writes, does layouts and inks while Mireault draws the thing. A very memorable and funny story I think about almost every time I'm in a drive-thru.More later, specifically about THE JAM and TO GET HER, but the subject matter of the latter is a bit too hard to really absorb right now.
