Melt the margarine. Add the onion, carrots, bay leaf and thyme and sauté until the mixture turns light brown. Add flour and mix until it achieves a rough texture. Let the mixture cool. Mix the tomato paste, warm broth or water together and then, using a wooden spoon, slowly add it to the mixture that has cooled. Mix it for about half an hour and bring to a boil over moderate heat. When it boils, add the milk. Cook for 5 more minutes over low heat. Pour the soup through a fine strainer and put into a clean bowl. Put the ETİ Pizza crackers into hot butter and the remove them immediately. Serve your soup with grated kaşar cheese and ETİ Pizza crackers.