Limited - Meal expenses/ business lunch

SOLVED

Hello,

I just wanna know how to post a business lunch receipt in a right way.

First of all I would enter the whole amount into Sage.

For example: Meal $ 20 and Gst $1 / Bank acocunt $ 21

But I am not sure which account number I can use for the deduction?
Can I always deduct 50 % of the whole amount?

Is there something special I should know about posting things like that for a Limited?

What it better ... post deductions month by month or at the end of the year?

I hope somebody can help me .... Thank you in advance. Chris