Pre-heat the oven to 425°F.
In a large bowl, combine the pumpkin, onions and apples with the lemon juice, salt and pepper, a little freshly grated nutmeg and the caraway seed. Add the sausages and dress everything with a layer of EVOO, about 3 tablespoons, to coat. Arrange on a large baking sheet and roast for 30-40 minutes.
Heat the butter in small pan over medium heat. Whisk in the flour, 1 minute, then add the beer, reduce for half a minute more, then whisk in the stock, maple syrup and Worcestershire sauce. Add some coarse black pepper and thicken for a few minutes more to coat a spoon.
Serve the roasted sausages and squash doused with the gravy.