Monzo founder and Y Combinator partner Tom Blomfield has unveiled a new recipe app he’s built — but within hours the site has been flooded with user-generated instructions for items ranging from “snot pasta” to “pre-shitted pants”.
Since quitting the neobank in 2021, Blomfield has taken on a series of new challenges, becoming an active angel investor, a mental health advocate and a group partner at California-based startup accelerator YC.
Blomfield’s latest pursuit arrived this week in the form of Recipe Ninja, an AI recipe generator he “vibe coded” — using large language models (LLMs) to generate code for the app, rather than write it manually — over the last few weeks.
In a post shared on Hacker News on Tuesday night, Blomfield wrote: “Over the last 2-3 weeks, I vibecoded the recipe app that I always wished existed – recipeninja.ai . It now includes a fully interactive voice assistant so you don’t need to get your dirty hands over your new iPad when you’re cooking.”
Using Windsurf, an AI coding tool, as well as Anthropic’s Claude and Google’s Gemini LLMs, Blomfield made an app which talks chefs through recipes step-by-step, and can import and generate recipes. A blog post, published two weeks ago, details how exactly he did it — and his reflections on these AI coding tools.
Like a true Brit, Blomfield’s recipe choices — posted to the app a few hours after his Hacker News post — include “Christmas Turkey with all the Trimmings”, “Michelin Star Pork Loin” and “Italian Lasagne”.

However, it didn’t take long before some unprofessional chefs came into the kitchen — serving up some recipes sure to leave a bad taste.
Primordial soup
Over the past few hours, Blomfield’s app has been flooded with somewhat less conventional recipes, such as: “Deep Fried Baby Doll”, “Primordial Soup”, “Thick White Cum Soup”, “Snot Pasta” and “Cyanide Ice Cream”.

Other highlights include “Actual Cocaine”, “Dirty Drug Needles Sandwich” and “Refreshing Lemon Toilet Water”.
Back on Hacker News, amid comments asking whether this is an April Fool’s joke, and others asking people to please stop using the phrase “vibe coding”, there are some more serious reflections.
“People are putting disgusting nonsense in there. Maybe add an AI review step to block that stuff. Let them do the whole recipe, then just block it,” suggests ‘ilaksh’.
Harry Law, an AI policy researcher at the University of Cambridge, tells Sifted the incident serves as a reminder the technology remains “deeply unpredictable”.
“You should expect people to have at least as much fun with your app as you did making it,” he says. “In this case, that means accepting that people will instantly use your recipe platform as a Trojan horse for information about explosives and controlled substances.”
Law adds: “Vibe-coding is powerful, but it’s also brittle. Its rise might show us that product, policy, and governance people aren’t just humourless hall monitors — they might actually be useful if you want to stop your app from telling people how to make cocaine.”
Startup highs and lows
Blomfield is no stranger to the highs and lows of building consumer apps. In 2021 he left Monzo, the London-based digital bank he cofounded in 2015, amid a turbulent time for the company; losses were growing, and in 2020 it raised funding at a 40% valuation cut.
He was open about the personal toll running the business had taken, and the impact on his mental health, telling TechCrunch in an interview that he had been “really struggling”. Two years ago, he moved from London to San Francisco and joined famed accelerator YC.
Blomfield tells Sifted he built Recipe Ninja as a side project to see what AI could do. “And honestly, I was pretty astonished with the progress in capabilities over the last few months.
“It’s nice to see it getting so much attention […] I obviously haven’t built content moderation yet. But I will do that now,” he adds. “Entirely with AI. Shall we see how long it takes to put in place something? My guess is about 30 minutes.”
Blomfield subsequently confirmed “basic content moderation” was now in place on Recipe Ninja.
Read the orginal article: https://sifted.eu/articles/tom-blomfield-ai-recipe-app-trolled/