Monica joined Matt Baker and Alex Jones on the BBC One show to chat about all manner of cookery topics, but the show veered from light entertainment to vomit-inducing in the blink of an eye.
Alex has no-one but herself to blame for what happened next when she quizzed Monica on whether it was true that she'd thrown "her thumb in the bin once". It turns out that this indeed happened - and we warn you that this anecdote is truly stomach-churning.
"I was doing a cooking demonstration, and this little girl says, 'I'm a big fan. Can I come up and cook with you?' I was like, yeah, yeah, come up with me," she remembered.
As you can probably imagine, this story is about to get very dark…
Monica went on: "So, she had to cut up some stale bread for croutons. I picked up the knife and I went to show her what to do, and the guy off-stage asked me a question. I looked up and I just crunched down - it took the top of my thumb off!"
By this point, there were audible groans in the studio from Matt and Alex, but Monica pressed on with this horrific story: "So, I have this little girl, who I think was about eight years old, and I didn't want to freak her out so I just swept [my thumb] into the bin and hid my hand behind my back.
"I didn't want her to see that it hurt, but she says, 'Are you alright, you're dripping [blood] all over the floor?' I was like, yeah, it's fine! I was shaking! I got through the demonstration, and I said, 'Look, I can't take any questions today'.
"I got in the back to the medics, who tried to stitch it back on, but it was gone. Anyway, they fixed it. It's a bit crooked [now]."
There you have it. Don't say we didn't warn you...
The One Show airs Mondays through Fridays at 7pm on BBC One.
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