Heat a large cast-iron skillet over medium-high heat. In a medium bowl, toss together tomatillos, jalapeños, and oil. Place mixture in skillet; cook until slightly charred and tender, 1 to 2 minutes per side. Transfer to a plate. Let stand until cool enough to handle. Seed and chop jalapeños.
In the work bowl of a food processor, place tomatillos, jalapeños, and all remaining ingredients; pulse until finely chopped. Cover and refrigerate for at least 30 minutes before serving.
Recipe by Southern Cast Iron at https://southerncastiron.com/brisket-hot-tamales/