Thanks.
But I still don't understand how that stew may increase the building skills. The villagers exercise but they don't go to build more for that.
PS: They bangs against the corner of the roof (at the top to the right)of the "sewing hut"

it is just a function built into the game

when the villagers eat certain stews, they exercise

when they sucessfully complete a round of exercising, the game gives them building experience points for it

perhaps for keeping physically fit so they will be strong enough to be good builders!

Thanks! I didn't know that! (hum.. I didn't understood, I have to work more my English!)
Effectively, it doesn't happen often!!

its not really common knowledge, and not something you would typically notice, so not knowing is okay!

and your english is fairly good