In a large bowl, sift together flour, baking soda and salt. Set aside.
Cream butter and 3/4 cup sugar until light and fluffy. Beat in egg, mixing until just combined. Add lemon zest and juice. Blend in flour mixture, mix to thoroughly combine.
Wrap dough in plastic and chill for 1 hour.
Preheat oven to 350 degrees Fahrenheit (176 C).
Combine pistachio nuts and 3 tablespoons sugar. Shape dough into 1-inch balls. Roll balls in pistachio-sugar mixture. Place 2 inches apart on un-greased baking sheets. Press cookies down with a small glass to flatten slightly.
Bake 10-12 minutes until golden. Transfer to racks to cool.