We visited Casa Modesta in a hot August evening, hoping to grab a set in the terrace but they were all taken! Instead, we had to go inside to a small nice room with some 20 seats. The decoration is simple, with some agricultural tools and the ambiance is not fancy - as the name suggests, it is a modest and unpretentious restaurant.
The menu has local plates and some portuguese mainstream dishes and they all sound good. We chose traditional food from Alentejo and it was served in giant portions (we really had to struggle to finish, and still couldn't). The desert had some ice-creams and home made traditional deserts which were good. The wine was also ok. The price ended up being fair but not too modest.