Baby Formula, No Milk??

Hi everybody
My wife and i had a new born 3 weeks ago. All good apart from my wife not having enough milk on some days.
Its like every third day that she doesn't produce as much as he can take.
I had to buy Organic formula for him which we try to give him only when there is no other choice.
I also bought a tea which has fenugreek herb and few others in it.
Does anyone have any suggestions how to boost up milk production, eg foods to eat and not to eat?
Thank you Tweet