Sometimes small pieces of food can get lodged in the nasal passages, usually when you suddenly and unexpectedly cough or choke while eating. Sometimes, however, there is nothing stuck there at all, but rather it is just irritation of the nasal passages from the choking incident that creates the sensation of having something stuck.
Assuming you are not having any trouble breathing or talking, then this is not an immediate medical emergency, and you could try sitting quietly for a little while to see if the sensation subsides. You could also try blowing your nose, as that may sometimes dislodge any stuck food particles.
Of course, if you are having trouble breathing, you should call an ambulance and get immediate help in an emergency room. Also, if the sensation doesn't subside or if the food particle does not dislodge, then you will need to get help from your doctor
to take a look inside your nose and throat to figure out if there is something there that needs to be removed. An ear, nose, and throat doctor
is the person best qualified to do this, as they can take a look inside with a special small camera. If you have an ENT doctor, you could call them directly or, alternatively, go to an emergency room which will likely have an ENT doctor on call. Good luck!