Q422: If imam forgets to read Surah Fatiha in salah

Question

our imam in fard nimaz forgot to recite sura fath instead recited sura ikhlaas and went to ruku after finishing ruku perhaps he remembered he abandoned salaah and asked to start a fresh–should he have continued salah and did sajda suhu at the end instead of abandoning salah or it is the correct action to read afresh .please explain

Answer

He should have continued salah and performed sajda-e-sahw as reading surah Fatiha is wajib.