Place beef chuck pieces into bowl, season with salt. Add all purpose flour, mix well until each piece is covered in flour.
Heat 2 tablespoons olive oil in a frying pan on medium heat, add the flour-covered beef, and cook until golden brown. For this make sure the beef pieces don’t have excess flour. Do not overcrowd the pan otherwise the beef will not cook evenly. Work in batches if needed. Set aside when done.
Add two more spoons of olive oil in the same pan then fry the onion and garlic on medium heat.
Once the onion and garlic are golden, add the carrot and celery and cook for 5-10 minutes until they soften.
Set the slow cooker on high heat, add the browned meat, cooked veggies, and cubed potatoes. Mix well.
Add Guinness, beef stock, bay leaves and thyme.
Salt and pepper to taste.
Cook on low for 6-8 or until your potatoes are soft and the broth has thickened. (or 4-5 hours on high)