Heat oven to 425°F. Arrange the eggplant planks on two rimmed baking sheets, brush both sides with oil, and season with salt and pepper. Roast until the eggplant is tender and lightly browned, about 20 to 25 minutes, switching and rotating the sheets halfway through.

While the eggplant roasts, heat the remaining oil in a medium saucepan over medium heat. Add the garlic, oregano, and pepper flakes and cook until fragrant. Stir in the tomatoes and their reserved juice, then simmer until the sauce has thickened slightly, about 15 minutes.

Pulse the bread in a food processor until fine crumbs form. Add the ricotta, most of the Pecorino, most of the basil, and lemon juice, then pulse until the mixture is well combined and creamy.

Spread the tomato sauce into the bottom of a 9 by 13-inch baking dish. Place a generous spoonful of the ricotta mixture onto the wider end of each eggplant plank and roll tightly.

Arrange the eggplant rolls seam-side down in the baking dish and sprinkle with the remaining Pecorino. Bake until the sauce is bubbling and the rolls are heated through, about 15 minutes.

Garnish with the remaining basil and serve warm.