Also true that those food deserts are perfectly okay with most of the people who live there. Culinarily speaking they never left 1970. Except for Starbucks. Everywhere there’s a Starbucks, where you can get those liquid coffee-flavored desserts.
Since I eat out about four times a year, and my groceries are rarely anything but staples – I never eat fast food, or take-out, or prepared foods from stores – there are many things on this list I’ve never had, and may never.
Cruffins!
Cross between a croissant and a muffin. The muffin part seems to be that it’s made in a muffin pan and comes out shaped like one.
Tres yummy!
Also, the cronut, created in 2013.
I was impressed the first time I had burrata because I had just read an article about how it was only made in Italy and had to be flown in fresh. Today you see it on Italian menus everywhere and you can buy it in the grocery store.
Well, some grocery stores. There are four grocery stores within a couple miles of me. The two largest ones have it. The two smaller ones don’t.
Thomas, the English muffin people, now offers croissant bread. Yep, just a big croissant in the shape of a (sliced) loaf and makes for some really good French toast.
How about macarons? Popped up everywhere about 10 or so years ago.
It’s delicious.
Standard fare at Parisian pâtisseries for decades before that, I’m pretty sure.
Yes, there are undoubtedly a few new foods, but as a general comment, a major change in about the last 40 years or so has been the discovery (in the US and Canada) of wonderful ethnic foods from around the world. There are various places on the internet that feature illustrated recipes from the 1950s, and what stands out is the dullness, sameness, and lack of strong flavours in most of these dishes. Not only were many foreign foods virtually unknown, but these folks appeared to be allergic to spices – mainstream recipes tended to be bland.
Sometime back around the 80s, the president of a major supermarket chain here (Loblaws, run at the time by Dave Nichols) was a true foodie and spent much of his time traveling the world and bringing the exotic flavours of foreign foods back home, enshrined in the “President’s Choice” (PC) brand of products. The first and most famous of this product line was the PC line of international sauces. Today there are all kinds of products along those lines, like about a dozen different Asian frozen soups.
There are a great many reasons for the discovery of interesting foreign foods, probably including more diverse immigration and the ubiquity of the internet, but in his own small way Dave Nichols probably helped change the culinary landscape. Anyone pining for the 50s as an idyllic decade ought to remember that among its many other social problems, the food was blech! Check out James Lilek’s Gallery of Regrettable Food! Did they have Asian food? Of course they did! Who wouldn’t love LaChoy™ brand chop suey in a can! Open a can, and dump some glop onto a plate! What could be more appetizing? 
I saw croissant hamburger buns last week. 50% off. 
Passionfruit anything seems to still be taking off, similar to matcha. Both are flavors that are well known in their native area, and have been spreading around the globe.
Still seeing more and more zero-alcohol gin, tequila, etc., plus non-alcoholic beer. We’re going on a cruise later this year, with the same company as last year’s cruise.
The really ridiculous thing is that everyone recognizes passionfruit flavor. It’s not at all foreign, it’s just something that most people probably don’t identify as “passionfruit”, but rather some sort of generic tropical fruit. Guava’s the same way- everyone knows it, but if you forced them to describe it, they’d probably say “Hawaiian Punch”.
Sounds like a license to sell air.
At an inflated price perhaps? 
Sounds pretty flaky of them to do that.
It’s not clear in this thread whether you’re talking about foods that were invented recently (whatever recently means) or foods that have only become known in the U.S. in recent times. No one has mentioned the history of pizza in the U.S. yet. As recently as the mid-1950s, pizza could only be found in restaurants in big American cities with Italian neighborhoods. The America pizza chains only came into existence in the mid-1960s. Pizza is now as standard as hamburgers and hot dogs as parts of meals in the U.S.
I think it’s clear the OP was asking about completely new dishes being invented now. Not about longstanding cuisine from elsewhere just now reaching widespread American or worldwide awareness.
But the thread has a life of its own, and most folks are talking about the second idea, not the first.
What about new variations on old dishes…
for example, Hawaiian Pizza was only invented in 1962 in Canada.
And don’t forget wars. American servicemembers get stationed in exotic locations, try the local food because anything’s better than Army mess, and discover that it’s actually pretty good.
Sometimes it works the other way - like when Koreans started using Spam as a stew ingredient after they were introduced to it by American servicemen.
I also recall seeing a guidebook for the southwestern US from the 1950s – not even a foreign country. Every entry for a restaurant that might be labeled Tex-Mex or New Mexican included a sentence that basically boiled down to “Don’t worry! You can still get a good steak here, too,” to reassure the reader that they’ll be able to get something they like there if they find foods like “tacos” to be too exotic for their taste.