Preheat broiler. Cut tomatillos into large chunks; set aside.

Broil peppers on an aluminum foil-lined baking sheet 5 inches from heat 3 to 4 minutes on each side or until peppers look blistered. Place peppers in a large zip-top plastic freezer bag; seal and let stand 10 minutes to loosen skins. Peel peppers; remove and discard seeds.

Bring tomatillos, Hatch peppers, 1/2 teaspoon salt, onion, and next 5 ingredients to a light boil in a largesaucepan. Remove from heat, and cool slightly.

Process tomatillo mixture, in batches, in a blender until smooth, stopping to scrape down sides as needed (or use a handheld immersion blender, if desired).

Sprinkle pork with remaining 1 teaspoon salt and pepper. Sauté pork, in batches, in hot oil in a Dutch oven over medium-high, stirring often, 4 minutes or until browned.

Add tomatillo mixture to Dutch oven, stirring to loosen browned bits from bottom of Dutch oven. Bring to a light simmer; cover, reduce heat to medium-low, and simmer, stirring occasionally, 1 1/2 hours or until pork is fork-tender. Uncover and cook, stirring occasionally, 30 minutes or until liquid is slightly thickened. Serve with tortilla chips, flour tortillas, or cornbread.