The above guide is incorrect this takes place in Chapter 1
Stand outside the Cathedral Main gate
Head Right into the Kitchen
infront of Brother Millius is a bowl of seeds
interact with the bowl then talk to him about it.
Head to the Toll Booth near the bridge you entered the town on.
Take a left into the woods
and pick up the nuts
Return to the kitchen
Equip the nuts then place them in the bowl
Talk to Millius and he will say i guess were growing a beech tree then
Achievement will unlock