Preheat oven to 450°. Trim fat from tenderloin, then cut tenderloin crosswise into 12 pieces. and pound each piece to 1/4-inch thickness.
Sprinkle pork evenly with salt and pepper. Heat a large skillet over medium-high heat. Add 1 teaspoon canola oil; swirl to coat. Add 6 tenderloin cutlets; cook 2 minutes on each side or until done. Remove from pan; keep warm. Repeat procedure with 1 teaspoon canola oil and remaining cutlets.
Return skillet to medium-high heat. Add remaining 1 teaspoon canola oil to pan; swirl to coat. Add shallots and garlic to pan; cook 2 minutes, stirring occasionally.
Reduce heat to low, then add stock and mustard; cook 1 minute, scraping pan to loosen browned bits. Then stir in sour cream, and cook 1 minute. (If heat is too high, the sour cream can curdle.)
Serve pork with pan sauce. Sprinkle with fresh chopped parsley, and serve immediately.