PORK: Whisk juice, syrup & mustard in a glass measure until smooth and set aside.
Pat tenderloins dry & sprinkle all over with salt & pepper.
Heat oil in a heavy, oven-proof skillet over medium heat; add tenderloins and cook for 4 to 6 minutes, turning often, until golden brown on all sides.
Drizzle mango mixture over each tenderloin, dividing evenly and transfer the skillet to the middle rack of a preheated 400F oven for 20 to 25 minutes, basting every 5 minutes, until juices are no longer pink inside.
Remove tenderloins to a cutting board, cover loosely with foil and let rest for 10 minutes; slice very thinly.
SALSA: Combine all ingredients in a glass measure; serve with pork.