Spread the walnuts onto a baking sheet then toast until the nuts start to turn golden brown and become fragrant, about 45 minutes. Watch the nuts carefully as they bake, they burn quickly. Once toasted, set the walnuts aside to cool to room temperature.
Raise oven temperature 180 degrees C. Line baking sheets with baking paper. Whisk together the matzo cake meal, salt and potato starch in a bowl.
In a large bowl, beat the eggs, margarine and sugar together until smoothly combined. Stir the meal mixture into the wet ingredients until thoroughly combined then mix in the chocolate chips. Drop the dough by spoonfuls onto the prepared baking trays.
Bake in the preheated oven until lightly golden brown, 10 to 15 minutes. Remove the cookies from the baking sheets as soon as they are removed from the oven; cool on baking racks.