An entire can of chipotle chiles may sound like a lot, but because it is in the brine, the heat in the pork is subtle. Mexican oregano is stronger and not as sweet as the more typical Greek oregano, though that's an acceptable substitute. Leftover pork also freezes well for up to two months.
7 cups water, divided
2 tablespoons cumin seeds
2 tablespoons grated lime rind
1 tablespoon Mexican dried oregano
6 garlic cloves, minced
1/2 cup kosher salt
1/2 cup sugar
1 (7-ounce) can chipotle chiles in adobo sauce, chopped
2 cups ice cubes
1 (3-pound) boneless pork loin, trimmed
1/4 cup fresh lime juice
2 teaspoons freshly ground black pepper
1 teaspoon Mexican dried oregano
2 garlic cloves, minced
How to Make It
Combine 1 cup water, cumin, rind, 1 tablespoon oregano, and 6 garlic cloves in a small saucepan. Bring to a boil; remove from heat. Pour into a large bowl; cool to room temperature. Add remaining 6 cups water, salt, and sugar, stirring until salt and sugar dissolve. Stir in chiles. Pour salt mixture into a 2-gallon zip-top plastic bag. Add ice and pork; seal. Marinate in refrigerator 24 hours, turning occasionally.
Preheat oven to 450°.
Remove pork from bag; discard brine. Pat pork dry with paper towels. Combine juice, pepper, 1 teaspoon oregano, and 2 garlic cloves. Place pork in a roasting pan coated with cooking spray. Brush juice mixture over pork. Bake at 450° for 15 minutes. Reduce oven temperature to 325° (do not remove pork from oven); bake an additional 45 minutes or until thermometer inserted into thickest portion of pork registers 155°. Place pork on a platter. Cover with foil; let stand for 15 minutes. Thinly slice.