Gather your ingredients
Seat a colander or large strainer inside a large bowl
Cut the white and light green parts of the leeks into 1" pieces. By the way, I learned leeks are one of the seven symbolic foods blessed and served at a Sephardic Rosh Hashanah dinner.
Transfer leeks to the colander as you work
Rinse under cool running water, separating the pieces to dislodge as much grit as possible. Once the bowl is full, drain and refill. Soak the leeks for 5-10 minutes. Drain and rinse a final time.
Seed and coarsely chop the tomatoes, separately reserving 1 to 11/2 cups of their juices.
Heat the olive oil in a large saucepan over medium heat.
Carefully add the tomatoes without their juices.
Stir and mash the tomatoes as they cook for 3-5 minutes. I used a pastry blender to break up the tomatoes.
Stir in the garlic and cook another 3-5 minutes.
Add the leeks to the tomatoes and stir.
Stir in the reserved tomato juice. If you don't have enough, add water to the measuring cup until you have 11/2 cups. Cover and cook for about 1 hour until the leeks are soft and flavors have blended.
Add the lemon juice, then season with salt and pepper to taste. For a more concentrated flavor and drier consistency, cook uncovered. Otherwise cover and cook for another 10-15 minutes.
Serve right away or cool before storing. it tastes even better after the flavors have a chance to meld. Serve as part of an appetizer assortment, mezze style, or as a side dish over grains or pasta.