Heat 2 teaspoons canola oil in a 2 1/2-quart saucepan over medium heat. Add onion and garlic; sauté 3 minutes or until mixture begins to brown. Transfer onion mixture to a blender; add tomatoes, 1/4 cup water, espresso powder, cocoa, chile, 1 teaspoon Mexican seasoning, sugar, and 1/4 teaspoon salt. Process until smooth, scraping down sides if necessary.
Return tomato mixture to pan. Bring to a boil; reduce heat, and simmer, uncovered, 15 minutes or until thick, stirring often.
While tomato mixture simmers, place pork on a broiler pan coated with cooking spray; brush with remaining 1 tablespoon oil. Combine 1 tablespoon Mexican seasoning, kosher salt, and red pepper; rub over pork. Broil 16 minutes or until a thermometer registers 160° (slightly pink), turning once. Remove from pan; cover with foil, and let stand 10 minutes before slicing. Serve pork with sauce.