Heat olive oil in a large pot over medium-high heat.
Season the beef with salt and pepper, then brown in batches.
Remove the beef and set aside. In the same pot, add onions and garlic.
Stir in tomato paste and cook for a few minutes until darkened.
Return the beef to the pot along with Guinness and beef broth.
Add carrots, potatoes, thyme, and bay leaves; bring to a simmer.
Reduce heat to low, cover, and simmer for 2 to 3 hours.
Taste and adjust seasoning with more salt and pepper if needed.
Remove bay leaves before serving.