Pulse pita in a food processor until coarsely ground. Heat 2 tablespoons olive oil in a pan over medium-high heat. Add pita crumbs and cook, stirring, until golden and crisp, 3 to 4 minutes. Season with salt and pepper. Steam green beans in batches until bright green and crisp-tender, about 3 minutes. Transfer to a serving dish, drizzle with olive oil and lemon juice, and season with salt and pepper. Sprinkle with seasoned breadcrumbs.