Dry toast the coriander seeds, cumin seeds, black peppercorn, and peeled green cardamom in a skillet for 5 minutes over medium-high heat.
Transfer the toasted spices to a spice grinder or mortar and pestle. Grind into a fine powder and set it aside.
Method One: Finely dice the parsley, cilantro, jalapeño peppers, and minced garlic. Add them to a small bowl. Then, stir in the lemon juice, kosher salt, ground spice mixture, and olive oil.
Method Two: Add the parsley, cilantro, jalapeño peppers, minced garlic, and lemon juice to a food processor and pulse to combine. Then, stir in the kosher salt, ground spices, and olive oil.
Transfer the sauce to an airtight container and refrigerate for at least one hour before serving.
