In an airtight container or zip-top bag, combine the olive oil, lime juice, and Sriracha. Add the fish, toss to coat, and seal. Refrigerate for 30 minutes.
In a large skillet, heat the vegetable oil over medium-high heat. Remove the fish from the marinade and place it in the pan. Discard the marinade.
Leave the fish in place, for about 5 minutes until a brown, crispy layer has formed on the bottom. With a spatula, gently flip the fish over and cook for 4 to 5 minutes until the fish is cooked through. Transfer the fish to a cutting board and coarsely chop it.
In a bowl, combine the shredded cabbage, cilantro, and jalapeño to make a slaw.