Zest is a western style restaurant about 5 minutes walk from Ebisu Station. They serve all your typical drinks, plus have a special menu of margarita type drinks.
We just drank water though ^^;
We decided to go with the 750yen beef tortillas and we were surprised by the very small amount that was served to us.
We didnt want to spend more, so we went to subway and got a 6″ chicken sub for 410Yen. HAHA.
Here is a pic of the interior just at it opened at 8pm (holiday hours):