Heat the olive oil in a large pot over medium heat.
Season the beef with salt and pepper, then add to the pot.
Brown the beef on all sides, about 5-7 minutes total, then remove and set aside.
In the same pot, add the onions and garlic, sautéing for about 3-4 minutes until translucent.
Add the carrots, potatoes, and tomato paste; stir for another 2 minutes.
Return the beef to the pot, then pour in the Guinness and broth.
Add thyme and bay leaf, then bring the mixture to a simmer.
Cover the pot and reduce heat to low, cooking for 1.5 to 2 hours, stirring occasionally.
Taste and adjust seasoning before serving, removing the bay leaf.