In a large soup pot heat 3 tablespoons of olive oil over medium heat. Add the onions, garlic, rosemary, and thyme and saute until the onions are tender, about 2 minutes. Toss the beef cubes in salt and pepper and flour. Turn up the heat to med-high and add the beef to the pot. Cook until the beef is browned and golden around the edges, about 5 minutes. Add the Marsala wine. Using a wooden spoon, gently stir up all the brown bits off the bottom of the pan. Add the butternut squash and sun-dried tomatoes and stir to combine. Add enough beef broth to just cover the beef and squash. Bring the stew to a boil over high heat, then reduce the heat to low and simmer, covered, for 1 hour. Season the stew with additional salt and pepper to taste. Sprinkle with the chopped parsley. Serve with crusty bread alongside.