Bring a large pot of water to a boil. Fill a large bowl with ice water and set it aside.
Cut a shallow X on the bottom of each tomato. This will make peeling much easier. Place tomatoes in boiling water until the skin begins to peel back, about 30 seconds to 1 minute.
Transfer tomatoes into the bowl of ice water; set aside for 5 minutes. Remove tomatoes from water; peel off the skin with your hands and slice into quarters.
Transfer tomatoes into a large saucepan over low heat; stir in salt. Simmer, stirring occasionally to prevent burning, until slightly thickened, about 20 to 30 minutes.