2 butternut squash, peeled, cut lengthwise into 6-millimeter-thick planks (about 8 slices from each squash)
Vegetable oil, for frying
Extra-virgin olive oil, for frying
455 grams fresh mozzarella, thinly sliced into 16 slices
1 cup freshly grated Grana Padano
16 fresh basil leaves (or 1 for each slice of squash)
Preheat the oven to 425 degrees.
Warm the tomato sauce in a small saucepan. Pat the butternut- squash slices very dry with paper towels. Over medium heat, fill a large nonstick skillet with one centimeter of oil (equal parts vegetable and olive oil).
When a tip of a piece of squash sizzles when dipped in the oil, add half of the squash, and cook, turning once, until golden, about two minutes per side. Drain on paper towels, and season with salt. Repeat with the remaining squash.
Ladle enough tomato sauce into a 23-by-33 centimeter baking dish to cover the bottom, about one cup. Arrange the butternut squash in one layer (it is okay if they overlap), and top with the remaining 1-1/2 cups sauce. Add a slice of mozzarella to each piece of squash, and sprinkle the grated Grana Padano over all. Top each slice of mozzarella with a basil leaf. Bake until the squash is tender and the cheese is browned and bubbly, about 20 minutes.