Digital Spy spoke to Mitchell about the show, his favourite quotes, Robert Webb's Star Wars obsession and why Twitter is more than just "pointless minutiae"...
What can viewers expect from Was It Something I Said?
"It's a comedy panel show about quotations, so the backbone of it is questions about... which famous person said this? What were they talking about? From these two words, can you complete this famous quotation?
"So it's a quiz about famous quotations which allows us to talk about celebrities, about historical figures, about Shakespeare, about Confucius, about Britney Spears, about David Attenborough...
"We had really fun recordings and what I hope it is - and I think it's difficult having not seen any edited episodes to know - but we want it to be having lots of funny interesting facts, lots of irreverent chat off the back of it, and to have nice, funny, rude, informative stuff structured around a quiz that people can play along with at home. They can literally play along with it at home on Twitter."
Yes, there's a strong Twitter element to the show - how does that work?
"I have no idea! But watching any good quiz - I think people do this with Would I Lie to You? and they do it with University Challenge - you sit at home and say what you think is the answer...
"On Twitter, I think you can submit the answers [for our show] and get a score and you are, as it were, officially playing along. People increasingly whilst they're watching television are doing something on another device, so I think it's quite a good idea that we provide something to do on the other device that is at least to do with the programme they're supposedly watching!"
You're on Twitter, but what would you say to people who think it's a waste of time? That it's just pointless minutiae?
"Well, obviously they're welcome to their opinions and you couldn't look at Twitter and think that there aren't pointless things said on it a lot, but I think it's fun and it's a way that people can chat away with each other when there aren't people physically there to chat away with.
"Humans have an urge to converse and burble. If a person who said that about Twitter walked into a pub or a restaurant and they heard people chatting away and laughing, I don't think they'd go, 'Oh look at all the pointless minutiae, what are these people doing? They're wasting their time'.
"No, they'd say, 'That's healthy human interaction', so I think what Twitter is, at its best, is that [interaction] happening through the use of technology."
Was It Something I Said? is based around quotations. Do you have a favourite quotation?
"My favourite one - it's supposedly Voltaire, but it might be someone else - is 'I despise what you say but I'd fight to the death for your right to say it' and I think that's one of the wisest things ever said, whoever said it.
"I think it's particularly worth remembering at the moment when the concept of free-speech is somewhat threatened. I think there's a lot of talk about what people mustn't say and I feel very strongly that there's nothing really - other than a libel or a physical threat - there's nothing that you mustn't say, but you all have the right to reply.
"Basically, if everyone can say what they like, and everyone can say what they like in reply, then right will out. So that's my current favourite one. It's not a very funny one, I know!"
There are a lot of panel shows on TV - do you think there's a danger of overplaying that format and flooding the market?
"I hope not, because we're just filming one! I think people like the good ones and they don't like the less good ones. I find them tremendous fun, both to be on and to watch. It's not like making Citizen Kane - this isn't necessarily something people buy a box set of. It's for more casual viewing but I think that's one of the great things television is there for.
"Sometimes television is a thing you absolutely focus on because you're watching a box-set of The Sopranos and sometimes it's a thing you're laughing along with in a more casual way, and I think that's what a panel show does really well.
"And genuinely, I think if there were too many panel shows being made, Dave wouldn't exist, because that's a channel which allows people to watch panel shows on repeat constantly. That certainly seems to be a functioning business model. I think Dave might be part of the reason people perceive there are too many but actually it's evidence that there's a healthy market for them."
There are questions on the show based around film and TV dialogue. Which films and which TV shows have you seen so many times you're able to quote them word-for-word?
"I used to be able to quote Monty Python when I was a teenager, but I remember Robert Webb swears he knows every word of dialogue from Star Wars. I think he could just recite all of Star Wars, with laser noises as well.
"I know quite a few quotes from The Simpsons, I think The Simpsons is a quotable show. You know, 'Beer - the cause of, and solution to, all of life's problems'."
You've got a new show with Robert called Ambassadors - is that a comedy drama and less of a sitcom than Peep Show?
"Yes, very much on the drama side really. Hopefully it's got funny moments. I think the key distinction between a sitcom and a comedy-drama is that in a sitcom people are bad at their jobs, but in a comedy drama, they can be good at them.
"It's about some diplomats - I play an ambassador and Robert plays a deputy ambassador in a fictional -stan in South Asia. They're good at their jobs and under difficult circumstances they make all sorts of moral compromises under pressure from London and all that.
"It's credible, hopefully funny at times, but serious at times. It was very nice to do something in a slightly different genre. It was nice to do a bit of acting alongside all my sitting in a sparkly chair telling a joke.
"I would have missed a trick if I'd only ended up doing one or the other. I'm lucky to get the opportunity to do both and I need to keep reminding people that I am up for both sorts of job!"
Was It Something I Said? starts this Sunday (October 6) at 10.05pm on Channel 4.