Add the coriander, cumin, chili powder, garam masala, garlic powder, and cayenne to a bowl. Mix until combined then set aside.
Preheat the oven to 425˚F. Line a baking sheet with foil. Add the potatoes, olive oil, 1 teaspoon of kosher salt, 1/2 teaspoon of black pepper, and 1 tablespoon of the spice mix to a bowl. Toss to combine. Spread the potatoes out in a single layer onto the baking sheet. Bake for 35-40 minutes until the potatoes are tender and slightly crispy. Remove the potatoes from the oven and allow them to cool for 10-15 minutes.
Transfer the potatoes to a large bowl. Add in the mayo, dijon, Serrano pepper, lime juice, dill, cilantro, red onion, currants, green onion, salt, pepper, and the remaining spice mix. Season with the remaining 1/4 teaspoon kosher salt and 1/8 teaspoon black pepper. Fold everything together until combined. This is best served warm or at room temperature. Enjoy!