Season turkey tenderloins all over with salt, black pepper and cumin.
In a large skillet over medium high heat, add about 2 to 3 tablespoons olive oil. Once heated, add the turkey tenderloins and saute on 1 side. Add the potatoes to the pan, flip the turkey, when ready and place the pan into the preheated oven. Roast turkey and potatoes for about 15 minutes or until a meat thermometer registers 170 to 180 degrees F. Let turkey stand 10 minutes before slicing crosswise into 1/2-inch thick slices.
Meanwhile, in a blender combine mangoes, mint, lime juice, mustard, and ginger. Puree until blended. Add yogurt and puree until smooth. Serve 1/2 of the turkey with all of the sauce spooned over top and all of the sweet potatoes.
Reserve remaining turkey for Thai Turkey and Rice.