Place pork tenderloin between 2 sheets of heavy-duty plastic wrap; pound to 1/4-inch thickness using a meat mallet or small heavy skillet. Remove plastic wrap. Cut pork into thin strips. Combine pork, lime rind, and next 6 ingredients (through salt).
Heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Add shallots to pan; sauté for 4 minutes or until tender. Place shallots in a large bowl. Add oil to pan. Add pork; sauté for 3 minutes or until no longer pink. Add pork to shallots.
Warm tortillas according to the package directions. Spoon 1/3 cup pork mixture onto each tortilla, and top each tortilla with 1 1/2 teaspoons sour cream and cilantro. Fold in half.