In a small bowl combine flour, salt, and pepper and the stew meat, toss to combine.
Add olive oil in a heavy pot over high heat. Brown the meat on all sides, remove the meat with a slotted spoon or tongs and set aside on a plate.
Add the onion and garlic to the pot and cook for 3 minutes. Mix in the tomato paste and cook 2 more minutes.
Pour in Guinness, scraping all the brown bits from the bottom of the pan.
Add the beef back to the pot and add the beef stock. Cover the pot and reduce heat to low. Simmer covered for 1 ½ to 2 hours.
Add carrots to the pot and simmer uncovered for another 30 minutes. If the mixture seems to thicken, thin it out with a little extra beef stock. Start the mashed potatoes during the last 30 minutes while the carrots are simmering.
Peel and dice the potatoes, add them to a large pot covered with water. Boil potatoes until fork tender, or about 25-30 minutes.
Drain the potatoes, add them back to the pot turning off the heat and mash until smooth.
Add grated cheddar cheese, cream, and butter and mix well. You can keep the potatoes warm in the oven if needed while waiting to serve.
When the carrots are tender, remove the stew from heat and carefully taste for seasoning, add additional salt and pepper if needed.
Serve the beef stew in a bowl over mashed potatoes. Sprinkle with fresh minced parsley and thyme.