Toss beef with 1 tbsp of the oil
In a small bowl, season the flour with salt, pepper and cayenne
Toss meat with seasoned flour
Heat remaining 2 tbsp oil in a large skillet over high heat
Brown the meat on all sides
In small bowl or glass, mix tomato puree with water
Reduce the heat, add the onions, crushed garlic and tomato puree mixture to the skillet
Cover cook for 5 minutes on low heat
Transfer the contents of the skillet to a crockpot and pour half of the Guinness into the skillet
Bring Guinness to a boil and stir to dissolve the caramelized meat juices on the pan
Pour over the meat, along with the remaining Guinness
Add the carrots and potatoes, and top with thyme
Cover the crock and simmer over low heat for at least 4-6 hours
Stir when finished and add seasonings (salt and/or pepper) if needed. Serve hot.