1/2poundpasilla or poblano chilisseeded and chopped
1/2poundtomatilloshusked, rinsed and quartered
1teaspoonkosher salt plus extra for the shrimp
1teaspoonfresh ground pepper
1/2cupfresh cilantro leaves
Heat olive oil in a large skillet over medium high heat. Add chilies and half of the garlic and cook until chilis soften or about 5 minutes. Add the tomatillos and 1 teaspoon of salt. Reduce the heat to medium-low and cook, stirring occasionally until the tomatillos start to break down or for about 8-10 minutes.
Transfer the tomatillo mixture to a blender and puree. Set aside.
Melt the butter in a large skillet over medium high heat. Add the shrimp, salt and pepper and the remaining garlic. Cook for about 2 minutes or until the garlic becomes fragrant. Add the tomatillo sauce and saute for 2 more minutes or until the shrimp barely become opaque. Serve with sprinkled cilantro leaves.