1 cup finely shredded Asiago cheese, plus more for garnish
½ tsp. freshly ground pepper
½ tsp. salt
2 tbsp. all-purpose flour
2 cups low-fat milk
½ cup dry sherry (see Note), or 2 tablespoons sherry vinegar
1 tbsp. minced garlic
4 cups thinly sliced Brussels sprouts
4 cups sliced mixed mushrooms, such as cremini, oyster and/or shiitake
1 tbsp. extra-virgin olive oil
12 oz. whole-wheat fettuccine