Preheat oven to 300 degrees, with racks in upper and lower thirds. Wash and dry kale and divide between two rimmed baking sheets (kale will shrink as it cooks). In a small bowl, stir together oil and Sriracha and drizzle over kale; season with salt. Using your hands, toss to coat. Bake until kale is crisp and just beginning to brown at edges, about 35 minutes, tossing kale every 10 minutes. Let cool on sheets on wire racks.
To store, keep in a large zip-top plastic bag at room temperature, up to 3 days.