Add about a tablespoon of oil to a frying pan, heat on medium-low fire, and cook beef cubes until browned. Transfer beef and juice to a large pot.
Add another tablespoon of oil to pan, and sauté garlic and onion until lightly browned. Transfer to large pot (make sure to use all the flavor from the pan by heating a bit of water in the pan and pouring it into the pot).
Into the large pot, add the carrots, bay leaf, salt, black pepper, and 3 cups of water. Cover, and simmer on low fire for 2 hours.
Add baby potatoes to the pot. Cover, and simmer for one hour, or until potatoes are softened.
In a bowl, mix together Guinness, sugar, Smoked Spanish Paprika, and tomato paste. Then pour the mix into the large pot. Cover and simmer for one more hour, or until desired thickness (stirring occasionally to prevent burning).
Serve hot, with freshly ground pepper sprinkled on top. Or store in refrigerator overnight and enjoy the next day, since stews always taste better after a day or two.