Fettuccine with Pork, Greens, and Beans

INGREDIENTS

• 2 1/2 boneless pork shoulder (Boston butt)
• 8 garlic cloves, 4 halved, 4 finely chopped
• 2 kosher salt plus more
• 1 torn 1-inch pieces day-old crusty white bread
• 6 olive oil, divided
• 1 finely grated lemon zest
• 1 finely grated orange zest
• 1/2 crushed red pepper flakes
• 1 15-ounce can cannellini (white kidney) beans, rinsed
• 1/2 finely grated Parmesan, divided, plus more
• Freshly ground black pepper
• 2 bunches turnip greens or kale, center ribs and stems removed, leaves coarsely chopped
• 1 fettuccine