1. Heat a Dutch oven over medium-high heat. Add oil to pan; swirl to coat. Add leek; sauté 5 minutes or until tender, stirring frequently. Add farro and garlic; cook for 1 minute, stirring constantly. Stir in wine; cook 1 minute or until wine evaporates. Add 1 cup water; cook 8 minutes or until liquid is nearly absorbed, stirring frequently. Add 2 more cups water, 1 cup at a time, stirring until each portion is absorbed before adding the next (about 30 minutes total). Stir in remaining 1 cup water, squash, sage, salt, and pepper. Cover, reduce heat, and simmer 30 minutes or until squash is just tender, stirring occasionally. Stir in cheese; sprinkle with nuts. Serve immediately.