1. Shell the shrimps and set aside. Heat 1 tablespoon butter in a small frying pan and sauté the shrimp shells for 2-5 minutes, add 2 1/2 cups water and boil until reduced to half. Strain and set the stock aside. Discard shells.
2. Heat the other 2 tablespoons butter and sauté the onion and garlic until the onion is tender. Add tomatoes, bay leaf, cloves and shrimp shell stock. Cover and cook for 15 minutes. Strain. Return to the saucepan and add the potatoes. Cover and simmer until the potatoes are almost done, about 15 minutes. Add the milk, shrimps and corn. Cook, covered for 5 minutes.
3. Beat the egg yolks lightly. Beat 3-4 tablespoons of the hot soup into the yolks, then stir the egg mixture into the soup over low heat until it thickens slightly. Serve with a potato, 2 slices of corn and some shrimps in each plate.