When anyone of you begins eating, say:
Bismillāh.
And if you forget then when you remember, say:
Bismillāhi fī awwalihi wa ākhirih.
When anyone of you begins eating, say:
With the Name of Allah.
And if you forget then, when you remember, say:
With the Name of Allah, in the beginning, and in the end.
Reference:
Abu Dawud 3/347, At-Tirmidhi 4/288. See Al- Albani's Sahih At-Tirmidhi
2/167.