Preheat oven to 375 F and grease a large baking sheet with butter or line with parchment paper.
In a large bowl, using a spoon or electric mixer blend the egg and then add butter, brown sugar, vanilla extract. Mix until smooth.
In a medium bowl, mix buckwheat flour, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients and stir until completely mixed.
Lightly mix in the chocolate chips.
Roll dough into small balls about golf ball size and align on baking sheet.
Cook for 9-11 minutes, until the edges are golden brown.