Shrimp, leeks and cannellini beans

 

• 1teaspoon fresh lemon zest and 2 tablespoons juice
• 1teaspoon sweet or smoked paprika
• 2garlic cloves, grated
• Kosher salt and black pepper
• 1pound peeled, deveined large shrimp (tails removed)
• 4tablespoons unsalted butter (½ stick)
• 2large leeks, trimmed, then halved lengthwise, white and light green parts sliced crosswise ½-inch thick (or 1 large onion, minced)
• 1(15-ounce) can cannellini beans or other white beans, rinsed
• 2cups chicken stock or vegetable stock
• 2tablespoons finely chopped fresh parsley (optional)
• Toasted bread, for serving (optional)