- 3 pounds curly kale (see Cooks' notes)
- 4 tablespoons olive oil, divided
- 8 tablespoons finely grated Parmigiano-Reggiano, divided
- 2 teaspoons freshly ground black pepper, divided
- Fine sea salt, divided
- Special equipment: 2 very large bowls; 2 large (half-sheet 18- by 13-inch) rimmed sheet pans; parchment paper or nonstick foil
- Heat oven to 275°F with racks in upper and lower thirds.
- Line rimmed sheet pans with parchment or nonstick foil.
- Cut out and discard stems and center ribs from kale. Aim for 32 cups of leaves (use a 1- or 2-quart glass measure and pack leaves without crushing them). Wash leaves and dry well.
- Transfer half of kale to a large bowl. Toss with half of oil, rubbing leaves to make sure they are well coated, then toss with half of parmesan, pepper, and salt. Once the first half is in the oven, repeat with the other half of the kale.
- Working in batches, spread leaves in a single layer on lined sheet pans and bake, switching positions of sheets halfway through, until crisp, about 25 minutes. Transfer crisps with a metal spatula to baking sheets or platters to cool. Reuse parchment or foil for successive batches.