Remove the papery skin from the tomatillos and place them in 2 cups of boiling salted water for 10 minutes.
1 lb green tomatillos
Drain and reserve the liquid.
Place the cooked tomatillos in a blender or food processor with the Jalapeno peppers, cilantro, garlic, onion and ½ cup of the reserved liquid and process or blend to a smooth purée.
2 Jalapeno peppers, 1 bunch fresh cilantro, 2 cloves garlic, 1 onion
Transfer the purée to a bowl and set aside.
Heat a skillet and roast the pumpkin seeds lightly in 1 tablespoon of the cooking fat.
1 cup pumpkin seeds
Place the roasted pumpkin seeds in the blender or food processor with the chicken stock and process to a smooth purée.
1 cup chicken stock
Combine the tomatillo and the pumpkin seed mixtures together.
Reheat your skillet and heat the sauce with the remaining 2 tablespoons cooking fat until very hot. Season to taste with sea salt and freshly ground black pepper.
3 tablespoon cooking fat, Sea salt and freshly ground black pepper to taste