Where can I buy walnut flour?

I have seen pecan flour at the Gordon Food Service Store.

Can you sub hazelnut flour? I've seen that a little more frequently (Bob's Red Mill makes it, among others I'm sure).

Alternatively, you might try making walnut flour in a food processor. Be careful that it doesn't turn into walnut butter/paste by pulsing and keeping a close eye on it.

I Googled it and came up with this. It looks promising. Hope it helps.

http://nuts.com/nuts/walnuts/meal.html