Preheat Oven 425 degrees. Rinse and dry the tomatillos. Then spread the tomatillos out evenly on a baking sheet (I recommend lining it with foil for easy cleanup), along with the Serrano pepper. Roast in the oven for 15 minutes, or until the tomatillos start to brown on top and are cooked through.
Mix together the Buttermilk Powder, Dill, Parsley, Chives, Garlic Powder, Dried Onion, Onion Powder, Black Pepper in a separate air tight container.
Remove from the oven, and transfer the tomatillos and Serrano pepper to a blender or food processor. Add the garlic, cilantro, onion, lime juice, salt, and cumin (if using) to the blender or food processor, and pulse the mixture until it reaches your desired consistency. (Always be careful when blending hot mixtures, as they expand while blending.) Season to taste.
Place chicken in CrockPot then pour the Salsa Verde over chicken and sprinkle in 3 tbsp of Ranch Powder mixture ( refrigerate remaining ranch mix and us for dressings and dip). Cover and cook for up to 10 hours on low or desired doneness. NOTE: Mine only took about 6.5 hours.
Shred Chicken in the sauce. Use for taco's, sandwiches, salads....really the options are endless.
I portioned mine out into freezer bags for future use.