For relish, stir together mangos, onion, bell pepper, vinegar, mint, and salt and pepper in a medium bowl; cover and refrigerate until ready to serve.

To prepare pork on grill: Finely chop 1/2 cup almonds and stir in brown sugar and seasonings. Brush pork with oil then season with salt and pepper; roll in almond mixture, pressing into the surface. Transfer to a piece of heavy-duty foil and press any remaining nuts onto the top. Grill over medium heat, turning occasionally to brown each side, for 35 to 40 minutes or until the internal temperature reads 160°F on a meat thermometer. Let stand for 5 minutes before slicing.

To prepare pork in oven: Adjust oven rack to middle position and heat oven to 450°F. For the pork, finely chop 1/2 cup almonds. Stir in brown sugar and seasonings; transfer almond mixture to baking sheet. Brush pork with 1 1/2 tablespoons oil then season with salt and pepper; roll in almond mixture, pressing into the surface. Lightly spray pork with olive oil spray. Cook pork on foil-lined baking sheet until exterior is golden brown and meat reaches 160°F, 35 to 40 minutes, turning pork halfway through cooking. Let stand for 5 minutes before slicing.

To assemble, top sliced pork with mango relish and toasted almonds.