"Me importa un pimiento"= It matters to me a pepper*

Prolific expression meaning I don't care/ I couldn't care less. You can also hear: "Me importa un pepino", "Me importa tres pimientos / pepinos". For a more traditional expression, we also have "me importa un bledo" (used in Gone with the Wind movie)



Sinceramente, me importa un pepino / pimiento
Francamente, me importa un bledo
Lo que tú digas me importa tres pimientos /pepinos