Preheat oven to 400℉. Add tomatillos, onion, and garlic to a large rimmed baking sheet. Drizzle with olive oil and sprinkle with salt. Toss to coat. Roast for 30 minutes, or until tomatillos start to shrivel and get golden on the edges.

Preheat the oven to broil. Put the poblanos and jalapeños on a baking sheet and broil on high for about 15 minutes, turning the peppers a couple times in between. They should be black and charred when they're finished.

Put peppers in a bowl and cover with plastic wrap. Let sit for 10 minutes (this helps the skin come off easily). Once finished, peel the skin off the peppers and discard the seeds and stems.

Add tomatillo mixture and peppers to a blender and blend on high until smooth and combined. Season to taste with salt. Set aside.

Rinse and pat dry your pork shoulder. Combine chili powder, cumin, coriander, and salt in a small bowl. Rub spice mixture evenly on pork. Heat a large skillet to medium/high heat. Add the pork shoulder to the skillet and sear on all sides until crusty and golden. I did about 3-4 minutes per side. Add pork to slow cooker and pour the tomatillo sauce over the pork.

Cook on low for 10-12 hours, or high for 7-8. Once pork is finished, remove from slow cooker, discard the fat and bones, and shred. Add pork back into the slow cooker and stir in the cilantro. Season to taste with salt. Serve over rice with sliced radish, extra cilantro, cotija cheese, and your favorite hot sauce!