Line a large cookie sheet or baking tray with parchment paper.
Rinse all the veggies.
Cut the top of the stem off the poblano and anaheim pepper. Cut in half lengthwise (from root to tip) and take out the seeds. Cut in half again, to end up with 4 pieces of each. Set aside.
Cut the ends off a small white onion, then cut in half. Set aside.
Peel 7 cloves of garlic. Set aside.
Take husks off tomatillos if you haven't already. Set aside.
Add all veggies to the parchment lined baking sheet, add 4 sprigs of oregano.
Drizzle the veggies with oil, and sprinkle with about 1 tsp of kosher salt.
Place baking sheet in the oven and roast for 30 minutes.
Once 30 minutes are up, use tongs to put everything in a blender.
Add 1/4 tsp cumin, and 1/3 cup cilantro to blender and pulse until everything comes together, about 10 seconds.
Taste the sauce and add 1/2 tsp kosher salt if it needs more salt.