Heat 1 teaspoon oil in a large nonstick skillet over medium-high heat. Sprinkle both sides of pork with jerk seasoning, salt, and red pepper. Add pork to pan; cook 4 minutes on each side or until done. Remove pork from pan; cover and keep warm.
Add remaining 1 teaspoon oil to skillet. Add pineapple, reserving 2 tablespoons juice. Add onion; cook 2 minutes or until lightly browned, stirring frequently. Stir in lime juice, jalapeño, and reserved pineapple juice. Serve warm salsa over pork.