Combine the first 9 ingredients in a medium bowl. Cover and refrigerate salsa until needed. Preheat grill to medium-high. Brush halibut with the 2 Tbsp. olive oil; season with salt and pepper. Brush the grill lightly with oil. Grill fish 3 to 4 minutes per side, or until just cooked through. Plate the fish, top with salsa and serve.