Although it is difficult to make a rational diagnosis without a proper clinical examination or at least a clinical photograph, if we go by the description you have mentioned, it seems that either you have got a traumatic ulcer (which could have been caused by a physical trauma or thermal injury)  reaction to any of the ingredients in that dish. It would be prudent to get yourself examined properly by a dentist. For symptomatic relief you can use anaesthetic ointments containing lignocaine or benzocaine. Regards.