3-4 dozen, depending on size
Place shelled pistachios on a cutting board and chop until you have a mostly a fine consistency, with some course pieces. Set aside.
Use a mixer to beat the margarine and sugar until light and fluffy (about 2 minutes). Beat in the vanilla extract.
In a small bowl combine the flour and salt and whisk together until combined. Add the flour mixture to the margarine mixture and beat for another minute or so until everything is combined.
Stir in the chopped nuts, cover and refrigerate the dough for about one hour or until firm.
When you're ready to begin baking, heat your oven to 350F. Then form the chilled dough into 1 inch balls (or smaller) and place them 2 inches apart on an ungreased baking sheets. I used a fork to flatten them just a bit (to make a place for the frosting to sit). Bake for about 12 – 15 minutes, or until the edges of the cookies start to brown. Remove from oven and place on a wire rack to cool.
In the meantime, make the Matcha Frosting by mixing powdered sugar, matcha and margarine together. Once it’s thoroughly mixed, add the vanilla and soy milk until you reached a desired consistency. Note: I recommend starting with 1 teaspoon of the matcha, then tasting it to determine if you'd like to add more.
After cookies have cooled, top them with frosting. I used a decorative nozzle to add a little more flair to the frosting.