Grill or grill pan on medium-high heat. Add pineapple and cook until edges begin to brown, about 2-3 minutes per side.

Cool pineapple, then chop into 1/2 inch pieces.

Combine the pineapple with the onion, jalapeño, cilantro, lime juice, oil, and salt.

Rest 10 minutes, then taste and adjust salt if needed.