Leaves fall in fall. Temperatures, too. But some things rise, our appetites topping the list. Salads are splendid, and the grill has its thrill, but come autumn, its rib-sticking fare we crave. Pasta offers the ideal canvas, whether for a sauté of woodsy mushrooms splashed with sherry, a warm-spiced ragu, savory sausage partnered with dark leafy greens, or an earthy spin on pesto that has as little to do with summer as it does with basil. So bring a pot of water to a rolling boil (it will help drown out your growling stomach). These hearty, delicious pastas promise to satisfy.