Bello! Next month sees the return of everyone’s favourite small, cute, bright yellow blob assistants who spout international gibberish, as Minions & Monsters is released in time to clean up over the US Independence Day box office weekend.

It’s the seventh instalment in the Despicable Me franchise and the third standalone outing for Kevin, Stuart, Bob et al. The series has so far earned £12.3bn globally, of which box office accounts for about half (with merchandise sales slightly outstripping it, and DVD sales coming in at a mere $725m).

Pierre Coffin has directed all but two of these films, which he told the Guardian 11 years ago are all rigorously focus-grouped by his own children.

Every time I work on a scene or I work on the overall movie, I had my kids unconsciously in mind. Is that going to please them? Is it going to be funny for them? And if it is funny for them, is it going to be funny for their friends and their friends’ friends? I show them pretty much everything before it gets anywhere near the final cut so they also get to see all the sucky stuff I miserably fail on and the stuff I have doubts on.

“If it’s meant to be provoking some kind of a comedic reaction and if it fails then you say: ‘OK, back to the drawing board.’

“I totally trust their judgment and I suppose I use them in quite a sneaky way to try to get the truth out of them because my theory is that if you put kids in front of a movie or a TV series, they have a tendency to gullibly like everything and if they don’t like it, it’s only a sort of mild dislike. They’re not going to hate it; they’re just going to say it was good. It’s a subtle difference but if that’s the case you can tell something’s not quite right.”

The son of a French diplomat and an Indonesian novelist, Coffin spent his childhood in Cambodia and Japan before the family settled in a Parisian suburb in the 1970s.

Banned from watching TV, Coffin read a lot of comic books and did industrial quantities of doodling, before training as an animator in Paris and having a brief spell in London working on Steven Spielberg’s We’re Back! A Dinosaur’s Story (1993).

The evolution of the minions was an unexpected one. “In the first film, they were depicted as this big army of muscular thugs doing the dirty work of the arch villain Gru,” he said, “and we quickly realised that they were very unappealing and made Gru a totally unsympathetic anti-hero.

“To make him charming, we had this idea that he’d know all of his little helpers by their forenames, even though there were hundreds, and suddenly Gru was sympathetic. We then put goggles on them, added workers’ overalls, making them look like these subterranean mole men-type creatures, gave them an increasingly saturated yellow skin tone and then they became the Minions. And from that first scene we knew they gave the other characters counterbalance, had great comedic potential and were super cute.”

The new film – set in 1920s Hollywood – is pre-Gru, but does feature voice work from Jesse Eisenberg, Trey Parker, Allison Janney, Christoph Waltz and Jeff Bridges.

So please post your questions for Coffin in the comments below by 9.30am BST on 19 June and we’ll publish his responses as part of our regular reader interview series on 3 July.