How to Make It
Slice pork lengthwise, cutting to, but not through, other side. Open halves. Place pork between sheets of plastic wrap; pound to 1/4 inch.
Combine 1 teaspoon olive oil, 1/4 teaspoon salt, 1/4 teaspoon black pepper, cumin, and red pepper in a small bowl. Brush pork with mixture. Cover and refrigerate for 1 hour.
Heat remaining 1 tablespoon oil in a large skillet over medium-low heat. Add onion; cook 20 minutes or until golden brown, stirring occasionally. Add 1/2 teaspoon salt, 1/4 teaspoon black pepper, rind, and next 4 ingredients (through sugar); bring to a boil. Cook 14 minutes or until liquid almost evaporates, stirring occasionally. Cool slightly.
Spread onion mixture over pork; leave 1/2-inch border. Roll, starting with long side. Secure pork with wooden picks.
Combine broth and wine in a large Dutch oven; bring to a boil. Add tenderloin; cover, reduce heat, and simmer 15 minutes or until a thermometer registers 145°. Remove pork from pan; keep warm. Bring cooking liquid to a boil; cook 8 minutes or until reduced to 1/2 cup. Strain cooking liquid through a sieve into a bowl; discard solids. Remove and discard wooden picks from pork; slice crosswise.