Heat the oil in a Dutch oven over medium-high heat. Add the beef cubes and brown them on all sides. Remove the beef and set it aside.
Add the onion, carrots, and celery to the pot. Cook for 5 minutes until the vegetables soften. Stir in the garlic and cook 1 minute more.
Pour in the ale and scrape the bottom of the pot to loosen any browned bits. Return the beef to the pot.
Add the beef broth, tomato paste, Worcestershire sauce, bay leaves, salt, and pepper. Bring to a simmer, then reduce heat, cover, and cook for 1 hour and 30 minutes until the beef is tender.
In a bowl, mix the flour, baking powder, salt, parsley, and thyme. Stir in the milk and melted butter until a thick batter forms.
Drop spoonfuls of the batter onto the surface of the simmering stew. Cover the pot and cook for 15 minutes without lifting the lid until the dumplings are cooked through.