In a large stock pot over high heat sear the pork in the vegetable oil until browned. Remove the pork from the pot, reserve 3 tablespoons oil in the pan.
Saut� the chopped onion and garlic seasoned with salt and pepper in the reserved oil until onions are tender. Add the cumin then stir in pork and chicken stock. Simmer for 1/2 hour. Add in Poblano, jalapenos and bell peppers.
Puree the tomatillos and cilantro in a blender, and add them to the pot. Cook for an additional 30 to 45 minutes.
Serve with Mexican/Spanish rice and refried beans.