Add the olive oil and butter to the pot over medium heat.
Generously season the beef with salt and pepper and once the butter melts, add the beef in a single layer searing on both sides. You may have to work in batches to get a nice sear on the beef.
Remove the beef from the pot and add the carrots and onions (if the pot looks too dry drizzle in a bit more olive oil). Season with salt and pepper and cook 3-4 minutes over medium/medium-high heat allowing them to get some color as well then remove them from the pot.
Fold in the tomato paste and grated garlic and cook a couple of minutes then pour in the beer and combine, scraping the brown bits from the bottom of the pot.
Return the beef, carrots and onions to the pot and add 2 1/2 cups of chicken stock, Worcestershire sauce and the bay leaf. Lay the thyme sprigs on top, cover and cook over very low heat 1 1/2 hours, moving the beef and veggies around occasionally, leaving the thyme sprigs on top.
After 1 1/2 hours, remove the lid and continue cooking about another 30 minutes. The beef should be nicely tender at this point.
Remove the bay leaf and thyme, then in a small bowl whisk the flour and 1/4 cup of chicken stock together. Fold it into the stew, gently combining and cook over low heat another 15 minutes. Taste and adjust salt and pepper as you like.
Serve with a good loaf of bakery style bread.