Heat the olive oil in a Dutch oven over medium heat. Add the beef cubes and brown them on all sides. Remove the beef and set it aside.
Add the chopped onion to the same pot. Cook until it softens. Stir in the minced garlic and cook for one more minute.
Sprinkle the flour over the onions and garlic. Stir well to coat everything.
Pour in the ale and scrape the bottom of the pot to loosen any browned bits. Let it simmer for two minutes.
Return the beef to the pot. Add the beef broth, butternut squash cubes, and chopped sage. Season with salt and pepper.
Bring the mixture to a gentle boil. Cover the Dutch oven and reduce the heat to low. Simmer for about two hours until the beef is tender and the squash is soft.