Most of my time in Poland was back in 2018, so not recent at all. I am an opportunistic diner in Europe--I want good food near my location when I get hungry. I'm rarely willing to make a reservation, so I usually eat in what I'd call "middle-class" places.
Poland has a lot of nice restaurants serving what I considered quality foreign cuisine. I speculate that some are owned and/or staffed by folks who spent time in western European restaurants when things opened up, saved their money and returned home to open their own businesses. That's just a guess, though. I'd say you shouldn't be unduly hesitant about trying restaurants offering foreign cuisines. (Maybe not Mexican or Central/South American, though; those seem to be a tough ask anywhere in Europe.)
A place I remember that is still open with a good rating follows. I don't claim it's worth building your trip around, but if it's convenient, I think it's worth a visit. It isn't dirt-cheap, and you certainly won't be the only foreigner eating there. Warsaw's not eactly awash with tourists, but it's a big business center, and I saw lots of people who seemed to be expats.
- Thai Me Up, Foksal 16. Thai, as you would expect. I've not been to Thailand and am not an expert, but I've eaten in a decent number of Thai restaurants over the year, and this place was better than all of them. It has an interesting menu. It's quite close to the National Museum and the Chopin Boutique Hotel, which is recommended by RS. I believe the folks behind this place are actually Thai, not well-traveled Poles.
There's a chain of crepe restaurants with locations in several Polish cities, including Warsaw. It's called "Manekin". I ate at least twice at Manekin locations, and the food seemed reliable. There's a large menu of savory as well as sweet crepes. Manekin is very popular; expect the atmosphere to be "bustling". You might have to wait for a table. I don't know whether they take reservations.
