Crona Cross's Favorite

I am looking for a isekai manga about 1 adult and a group of student transported to another world, when the adult guy got kicked out of the castel and set foot out of the capital with the information that he gotten there he meet a fefnir(?) Who got swayed by guy cooking the fefnir(?) Give a blessing to the guy and then he met a slime...
Sorry that's all i can i remember about this isekai manga.

anybody recommend me a manga where they bully a boy and didnt know he was strong? pleaseeee