This is a sentence in my English book:
I’m not very adventurous about eating - I look for international restaurant.
I expected to find adventurous pattern something like
adventurous about doing sth
or
adventurous to do sth
but the only information in both oxford dictionary and longhand is simple sentence and used an adjective before a noun.
I’m a bit puzzled by your question because the phrase in your book, “I’m not very adventurous about eating”, follows the pattern “adventurous about doing sth”, which you say you expected. So where is the difficulty?
“I’m not very adventurous to eat…” would be incorrect.
“I look for international restaurant” is incorrect. Possibly it was meant to say “I look for international restaurants”. Also, the hyphen in your sentence should be a dash (though it is not uncommon to see hyphens used for dashes because dashes are awkward to type on most keyboards).
the sentence is:
I’m not very adventurous about eating - I look for international restaurant chains.
but I can find this pattern in my dictionary
adventitious about doing sth
Dictionaries can’t list every possible pattern for every word: they don’t have enough room.
(By the way, second time you wrote “adventitious”, which is a different word altogether.)
I’m so sorry Dozy 
it really makes me confused 
So the pattern is adventurous about doing sth
“adventurous” can be used in various different ways in sentences. If you want to describe an aspect of someone’s behaviour that is or isn’t adventurous then you can use the pattern “adventurous about doing sth”. (You could also say “adventurous when it comes to doing sth”, or “adventurous as far as doing sth is concerned”, and probably other ways too.)