Backstory: There are a lot of Restaurant makeover shows, Kitchen Nightmares, Restaurant Makeover, Bar Rescue, and more. Other shows like top chef reward the winner with money to start their own, premiere restaurant. Diners Drive Ins and Dives is another one that showcases restaurants. A lot of times I'd love to follow up to see how the restaurants are doing but there's no way to find a list of them all.
The Idea: An as seen on TV restaurant tour.
Deep Dive: This could MVP as a simple google sheet or list of restaurants showcased on TV in certain cities along with the show they were features on, address and yelp rating. Once this gains traction, you could build a simple app to add more categories and features like a tour/itinerary for foodies and travelers. You could also add ratings and reviews which would be really interesting for those failed restaurants as a follow-up and progress meter.
Validation: I lived in Charlotte for a year and Cabo Fish Taco was recommended on Diners Drive Ins and Dives. That restaurant proudly displayed it's "as seen on tv" status and every time I visited there, someone was talking about the tv show.
Monetization: Before jumping right into the subscription model, you could charge a one-time fee for life-time access to each city's list. This would be a good way to "stair step" your way into the idea to prove people will pay for this information.