The shredded potatoes fried in Lanzhou Lamian Noodles are red with tomato sauce. Ketchup will be put in the first pot, and then fried with vegetables. After adding noodles, a spoonful of broth (some are chicken soup) will usually be put in, so that the fried noodles will bring some soup. Tomato paste is a concentrated product of tomato paste, which is made from mature red tomatoes through crushing, pulping, peeling and seed concentration, canning and sterilization. The finished product is bright red paste, which has the unique flavor of tomato.