Put a small cast-iron frying pan or heavy pan over medium heat. When the pan is warm, add the walnuts and stir until they are golden brown and toasted, 1 or 2 minutes. Set aside on a plate to cool. When cooled, coarsely chop the nuts. In a medium bowl, mix together the oats, golden raisins, chocolate chips, and chopped walnuts. In a separate medium bowl, whisk together the flour, baking soda, salt, cardamom, and cinnamon. Cream the butter, sugar, and jaggery in a mixing bowl. Beat in the eggs and vanilla until combined. Gradually add the flour mixture to the creamed butter and sugar to combine. Fold in the oats mixture. Make sure to not overmix. Chill the dough in the refrigerator for 20 minutes. Meanwhile, preheat the oven to 350°F and line a rimmed baking sheet with parchment paper. Scoop up about 2½ tablespoons of dough and gently roll into a ball. Place on the baking sheet. Repeat to fill the baking sheet, spacing the dough balls 2 inches apart. Wrap any remaining dough in clear plastic wrap in the shape of a log and store in the freezer to bake another time. Bake until golden brown on top and a smidge darker at the edges, 12 to 14 minutes, rotating the pan 180 degrees halfway through baking. Take the pan out of the oven. The cookies will be delicate, and some may look uncooked in places, but they will harden up as they cool. Cool the cookies on the pan for 5 minutes and then transfer them to a rack to cool further. (If baking additional batches, make sure your baking sheet is completely cool before putting more cookie dough on it.) You can store the cookies in an airtight container for up to 3 days.