A whole lot of food in restaurants in the US is just shitty, commercially purchased frozen stuff, not actually prepared in house. Most of the “dude I LOVE this little mom & pop place” recommendations are just the same thing - people with a deep fryer and a corporate account to buy everything in 20-lb bags. That’s where stuff like appetizers often come from, AFAIK it’s not uncommon for entrees to be in the same boat. So frozen sauces for spaghetti, lasagna, maybe?

I was never a food guy so I only pick it up in bits and pieces, but I’ve eaten out with enough grossed out culinary nerds to understand something is up