Place the pork between 2 sheets of plastic wrap. Working from the center, pound the pork flat into a 14 x 6-inch rectangle. Remove the plastic wrap.
Stir 1/2 cup salsa, the chorizo and croutons in a medium bowl. Spread the chorizo mixture lengthwise down the center of the pork. Fold the sides over the filling. Tie the pork crosswise at 2-inch intervals with kitchen twine.
Place the remaining salsa, orange juice, cilantro, brown sugar and mango into a blender. Cover and blend until the mixture is smooth. Pour the mango mixture into a 10-inch skillet. Heat over medium-high heat to a boil. Reduce the heat to medium-low. Cook and stir for 20 minutes or until the sauce is thickened.
Lightly oil the grill rack and heat the grill to medium. Grill the pork for 20 minutes or until it's cooked through, turning the pork over once halfway through grilling. Remove the pork from the grill and let stand for 10 minutes. Thinly slice the pork and serve with the mango sauce.
Tip: When choosing a mango, look for firmness. A ripe mango is slightly soft to the touch. It will continue to ripen at room temperature, so if you don't use it immediately you can store it in the refrigerator for about 5 days.