Sage Risotto with Fresh Mozzarella and Prosciutto

Diced mozzarella melts but doesn't completely crumble in this rice-based risotto. Small cheese pockets in a warm form will surprise and delight you. If desired, replace the sage with basil.
Bring the broth to a boil in a medium saucepan (do not bring to a boil). Keep warm over low heat.Melt the butter in a medium skillet over medium-high heat. Add the leeks and garlic; cook for 3 minutes, stirring frequently. Add the rice and 1/4 teaspoon salt; cook for 1 minute, stirring constantly. Pour in the wine; cook for 2 minutes or until the liquid is almost absorbed, stirring constantly. Add the broth 1/2 cup at a time, stirring frequently, until each portion of broth is absorbed before adding the next one (about 20 minutes in total). Add the chopped sage and cook for 2 minutes. Remove from heat; add mozzarella. Pour 1 cup of risotto into each of the 4 bowls; sprinkle each serving with about 1 1/2 tablespoons of prosciutto. Sprinkle with black pepper. Garnish with sage sprigs if desired.