Combine the first 4 ingredients in a medium bowl. Add pork; toss well. Heat 1 1/2 teaspoons oil in a large nonstick skillet coated with cooking spray. Add pork; sauté 3 minutes. Remove pork from pan; keep warm.
Heat 1 1/2 teaspoons oil in pan over medium-high heat. Add onion and garlic; sauté for 30 seconds. Add tomatillos; sauté 1 minute. Add pork; cover and cook 10 minutes or until pork is done. Add tomatoes and cilantro; cover and cook for 1 minute. Serve with rice.