The protein in ham and beans makes pasta e fagioli the basis for a balanced meal.
Bring a large stockpot of water to a boil, and cook pasta until al dente, about 8 minutes. Heat a low-sided 6-quart saucepan over medium-high heat, and coat with olive-oil cooking spray. Add ham, and saute until beginning to brown, 1 to 2 minutes. Add garlic and leeks; reduce heat to medium low. Saute until leeks have softened, about 5 minutes. Add beans; stir until well combined and beans are warm.
Remove 1 cup bean mixture; place in the bowl of a food processor with 1 can chicken stock. Puree until smooth; return to saucepan. Add remaining chicken stock, scallions, and pepper. When very hot, after 2 to 3 minutes, stir in reserved pasta; cook until heated through. Garnish with chives and Parmesan, if desired; serve.